There is hot, and then there is hot! Extreme heat is a period of high heat and humidity with temperatures above 90 degrees for at least two to three days. In extreme heat your body works extra hard to maintain a normal temperature, which can lead to death. Extreme heat is responsible for the highest number of annual deaths among all weather-related hazards.

Prepare for Extreme Heat

• Learn to recognize the signs of heat illness.
• Do not rely on a fan as your primary cooling device. Fans create air flow and a false sense of comfort, but do not reduce body temperature or prevent heat-related illnesses.
• Identify places in your community where you can go to get cool such as libraries and shopping malls or contact your local health department to find a cooling center in your area.
• Cover windows with drapes or shades.
• Weather-strip doors and windows.
• Use window reflectors specifically designed to reflect heat back outside.
• Add insulation to keep the heat out.
• Use a powered attic ventilator, or attic fan, to regulate the heat level of a building’s attic by clearing out hot air.
• Install window air conditioners and insulate around them.
• If you are unable to afford your cooling costs, weatherization or energy-related home repairs, contact the Low Income Home Energy Assistance Program (LIHEAP) for help.

Be Safe DURING

• Never leave people or pets in a closed car on a warm day.
• If air conditioning is not available in your home go to a cooling center.
• Take cool showers or baths.
• Wear loose, lightweight, light-colored clothing.
• Use your oven less to help reduce the temperature in your home.
• If you’re outside, find shade. Wear a hat wide enough to protect your face.
• Drink plenty of fluids to stay hydrated.
• Avoid high-energy activities or work outdoors, during midday heat, if possible.
• Check on family members, seniors and neighbors.
• Watch for heat cramps, heat exhaustion and heat stroke.
• Consider pet safety. If they are outside, make sure they have plenty of cool water and access to comfortable shade. Asphalt and dark pavement can be very hot to your pet’s feet.
• If using a mask, use one that is made of breathable fabric, such as cotton, instead of polyester. Don’t wear a mask if you feel yourself overheating or have trouble breathing.

Heat-Related Illnesses

Know the signs of heat-related illnesses and ways to respond. If you are sick and need medical attention, contact your healthcare provider for advice and shelter in place if you can. If you are experiencing a medical emergency call 9-1-1.

HEAT STROKE

• Signs:
  • Extremely high body temperature (above 103 degrees F) taken orally
  • Red, hot and dry skin with no sweat
  • Rapid, strong pulse
  • Dizziness, confusion or unconsciousness

If you suspect heat stroke, call 9-1-1 or get the person to a hospital immediately. Cool down with whatever methods are available until medical help arrives. Do not give the person anything to drink.

HEAT CRAMPS

• Signs: Muscle pains or spasms in the stomach, arms or legs

HEAT EXHAUSTION

• Signs: Heavy sweating, paleness, muscle cramps, tiredness, weakness, fast or weak pulse, dizziness, headache, fainting, nausea, vomiting

If you have signs of heat cramps or heat exhaustion, go to a cooler location and cool down by removing excess clothing and taking sips of sports drinks or water. Call your healthcare provider if symptoms get worse or last more than an hour.

What happens to the body as a result of exposure to extreme heat?

People suffer heat-related illness when the body’s temperature control system is overloaded. The body normally cools itself by sweating. But under some conditions, sweating just isn’t enough. In such cases, a person’s body temperature rises rapidly. Very high body temperatures may damage the brain or other vital organs. Several factors affect the body’s ability to cool itself during extremely hot weather. When the humidity is high, sweat will not evaporate as quickly, preventing the body from releasing heat quickly. Other conditions that can limit the ability to regulate temperature include old age, youth (age 0-4), obesity, fever, dehydration, heart disease, mental illness, poor circulation, sunburn, and prescription drug use and alcohol use.

Who is at greatest risk for heat-related illness?

Those at greatest risk for heat-related illness include infants and children up to four years of age, people 65 years of age and older, people who are overweight, and people who are ill or on certain medications.

What is heat stroke?

Heat stroke is the most serious heat-related illness. It occurs when the body becomes unable to control its temperature: the body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. Body temperature may rise to 106°F or higher within 10 to 15 minutes. Heat stroke can cause death or permanent disability if emergency treatment is not provided.

What are the warning signs of a heat stroke?

Warning signs of heat stroke vary but may include the following:

• An extremely high body temperature (above 103°F)
• Red, hot, and dry skin (no sweating)
• Rapid, strong pulse
• Throbbing headache
• Dizziness
• Nausea
• Confusion
• Unconsciousness

What should I do if I see someone with any of the warning signs of heat stroke?

If you see any of these signs, you may be dealing with a life-threatening emergency. Have someone call for immediate medical assistance while you begin cooling the victim. Do the following:

• Get the victim to a shady area.
• Cool the victim rapidly, using whatever methods you can. For example, immerse the victim in a tub of cool water; place the person in a cool shower; spray the victim with cool water from a garden hose; sponge the person with cool water; or if the humidity is low, wrap the victim in a cool, wet sheet and fan him or her vigorously.
• Monitor body temperature and continue cooling efforts until the body temperature drops to 101-102°F.
• If emergency medical personnel are delayed, call the hospital emergency room for further instructions.
• Do not give the victim alcohol to drink.
• Get medical assistance as soon as possible.

What is heat exhaustion?

Heat exhaustion is a milder form of heat-related illness that can develop after several days of exposure to high temperatures and inadequate or unbalanced replacement of fluids. Those most prone to heat exhaustion are elderly people, those with high blood pressure, and those working or exercising in a hot environment.

What are the warning signs of heat exhaustion?

The warning signs of heat exhaustion include the following:

• Heavy sweating
• Paleness
• Muscle cramps
• Tiredness
• Weakness
• Dizziness
• Headache
• Nausea or vomiting
• Fainting

The skin may be cool and moist. The pulse rate will be fast and weak, and breathing will be fast and shallow. If heat exhaustion is untreated, it may progress to heat stroke. See medical attention if symptoms worsen or last longer than one hour.

What steps can be taken to cool the body during heat exhaustion?

• Drink cool, nonalcoholic beverages.
• Rest.
• Take a cool shower, bath, or sponge bath.
• Seek an air-conditioned environment.
• Wear lightweight clothing.

What are heat cramps and who is affected?

Heat cramps are muscle pains or spasms – usually in the abdomen, arms, or legs – that may occur in association with strenuous activity. People who sweat a lot during strenuous activity are prone to heat cramps. This sweating depletes the body’s salt and moisture. The low salt level in the muscles causes painful cramps. Heat cramps may also be a symptom of heat exhaustion. If you have heart problems or are on a low-sodium diet, seek medical attention for heat cramps.

What should I do if I have heat cramps?

If medical attention is not necessary, take the following steps:

• Stop all activity and sit quietly in a cool place.
• Drink clear juice or a sports beverage.
• Do not return to strenuous activity for a few hours after the cramps subside because further exertion may lead to heat exhaustion or heat stroke.
• Seek medical attention for heat cramps if they do not subside in 1 hour.

What is heat rash?

Heat rash is a skin irritation caused by excessive sweating during hot, humid weather. It can occur at any age but is most common in young children. Heat rash looks like a red cluster of pimples or small blisters. It is more likely to occur on the neck and upper chest, in the groin, under the breasts, and in elbow creases.

What is the best treatment for heat rash?

The best treatment for heat rash is to provide a cooler, less humid environment. Keep the affected area dry. Dusting powder may be used to increase comfort.

Can medications increase the risk of heat-related illness?

The risk for heat-related illness and death may increase among people using the following drugs: (1) psychotropics, which affect psychic function, behavior, or experience (e.g. haloperidol or chlorpromazine); (2) medications for Parkinson’s disease, because they can inhibit perspiration; (3) tranquilizers such as phenothiazines, butyrophenones, and thiozanthenes; and (4) diuretic medications or “water pills” that affect fluid balance in the body.

How effective are electric fans in preventing heat-related illness?

Electric fans may provide comfort, but when the temperature is in the high 90s, fans will not prevent heat-related illness. Taking a cool shower or bath or moving to an air-conditioned place is a much better way to cool off. Air conditioning is the strongest protective factor against heat-related illness. Exposure to air conditioning for even a few hours a day will reduce the risk for heat-related illness. Consider visiting a shopping mall or public library for a few hours.

How can people protect their health when temperatures are extremely high?

Remember to keep cool and use common sense. Drink plenty of fluid, replace salts and minerals, wear appropriate clothing and sunscreen, pace yourself, stay cool indoors, schedule outdoor activities carefully, use a buddy system, monitor those at risk, and adjust to the environment.

How much should I drink during hot weather?

During hot weather you will need to increase your fluid intake, regardless of your activity level. Don’t wait until you’re thirsty to drink. During heavy exercise in a hot environment, drink enough non-alcoholic cool fluids each hour to maintain normal color and amount of urine output.

Should I take salt tablets during hot weather?

Do not take salt tablets unless directed by your doctor. Heavy sweating removes salt and minerals from the body. These are necessary for your body and must be replaced. The easiest and safest way to do this is through your diet. Drink fruit juice or a sports beverage when you exercise or work in the heat.

What is the best clothing for hot weather or a heat wave?

Wear as little clothing as possible when you are at home. Choose lightweight, light-colored, loose-fitting clothing. In the hot sun, a wide-brimmed hat will provide shade and keep the head cool. If you must go outdoors, be sure to apply sunscreen 30 minutes prior to going out and continue to reapply according to the package directions. Sunburn affects your body’s ability to cool itself and causes a loss of body fluids. It also causes pain and damages the skin.

What should I do if I work in a hot environment?

Pace yourself. If you are not accustomed to working or exercising in a hot environment, start slowly and pick up the pace gradually. If exertion in the heat makes your heart pound and leaves you gasping for breath, STOP all activity. Get into a cool area or at least in the shade, and rest, especially if you become lightheaded, confused, weak, or faint.

Warmer temperatures increase the risk for a diverse range of health risks. For example:

• An increased risk of hospitalization for heart disease.

• Heat exhaustion, which can lead to heat stroke if not treated, can cause critical illness, brain injury,
  and even death.

• Worsening asthma and chronic obstructive pulmonary disease (COPD) as heat increases the production of ground-level ozone.

• Dehydration, which can lead to kidney injury and blood pressure problems. Some kidney damage can become irreversible with repeated or untreated injury.

• Violence, crime, and suicide may increase with temperature, adding to the rates of depression and anxiety already associated with climate change.

• Some medications increase the risk of heat-related illness. These include diuretic medicines (sometimes called “water pills”), antihistamine medicines (including many allergy medicines), and many antipsychotic medicines used to treat a variety of psychiatric and neurologic illnesses.

Heat Stroke

WHAT TO LOOK FOR

• High body temperature (103°F or higher)
• Hot, red, dry, or damp skin
• Fast, strong pulse
• Headache
• Dizziness
• Nausea
• Confusion
• Losing consciousness (passing out)

WHAT TO DO

• Call 911 right away-heat stroke is a medical emergency
• Move the person to a cooler place
• Help lower the person’s temperature with cool cloths or a cool bath
• Do not give the person anything to drink

Heat Exhaustion

WHAT TO LOOK FOR

• Heavy sweating
• Cold, pale, and clammy skin
• Fast, weak pulse
• Nausea or vomiting
• Muscle cramps
• Tiredness or weakness
• Dizziness
• Headache
• Fainting (passing out)

WHAT TO DO

• Move to a cool place
• Loosen your clothes
• Put cool, wet cloths on your body or take a cool bath
• Sip water

Get medical help right away if:

• You are throwing up
• Your symptoms get worse
• Your symptoms last longer than 1 hour

Heat Cramps

WHAT TO LOOK FOR

• Heavy sweating during intense exercise
• Muscle pain or spasms

WHAT TO DO

• Stop physical activity and move to a cool place
• Drink water or a sports drink
• Wait for cramps to go away before you do any more physical activity

Get medical help right away if:

• Cramps last longer than 1 hour
• You’re on a low-sodium diet
• You have heart problems

Sunburn

WHAT TO LOOK FOR

• Painful, red, and warm skin
• Blisters on the skin

WHAT TO DO

• Stay out of the sun until your sunburn heals
• Put cool cloths on sunburned areas or take a cool bath
• Put moisturizing lotion on sunburned areas
• Do not break blisters

Heat Rash

WHAT TO LOOK FOR

• Red clusters of small blisters that look like pimples on the skin (usually on the neck, chest, groin, or in elbow creases)

WHAT TO DO

• Stay in a cool, dry place
• Keep the rash dry
• Use powder (like baby powder) to soothe the rash

The effects of rising temperatures and extreme heat result in numerous illnesses and deaths each year.

For many people, warm weather is a time for fun-filled outdoor activities. However, hot weather and outdoor activities don’t always mix well, especially during periods of extreme heat— times when temperatures are substantially hotter and/or more humid than average for a location and date.

Extreme heat can cause people to suffer from heat-related illness, and even death. People suffer heat-related illness when their bodies are unable to properly cool themselves. Older adults, young children, and people with chronic medical conditions are at high risk for heat-related illness and death. More than 700 people die from extreme heat every year in the United States.

Warmer temperatures can mean higher ozone levels. Pay attention to the U.S. Environmental Protection Agency’s Air Quality Index when planning outdoor summer activities, especially if you have asthma or another lung disease.

Track extreme heat in your area. The CDC Heat & Health Tracker provides local heat and health information so communities can better prepare for and respond to extreme heat events. You can use it to explore how extreme heat affects your county, populations that are at risk, and resources for response.

When temperatures are extremely high, take steps to protect yourself and your loved ones:

• Stay in an air-conditioned indoor location as much as you can.
• Drink plenty of fluids even if you don’t feel thirsty.
• Schedule outdoor activities carefully.
  • Wear loose, lightweight, light-colored clothing and sunscreen.
  • Pace yourself.
• Take cool showers or baths to cool down.
• Check on a friend or neighbor and have someone do the same for you.
• Never leave children or pets in cars.
• Check the local news for health and safety updates.

People aged 65 years or older are more prone to heat-related health problems. If you’re an older adult or a caretaker, review this information on how you or the person you’re caring for can stay safe during the heat.

Why are older adults more prone to heat stress?

• Older adults do not adjust as well as young people to sudden changes in temperature.
• They are more likely to have a chronic medical condition that changes normal body responses to heat.
• They are more likely to take prescription medicines that affect the body’s ability to control its temperature or sweat.

Stay cool, stay hydrated

• Stay in air-conditioned buildings as much as possible. If your home doesn’t have air conditioning, contact your local health department or locate an air-conditioned shelter in your area.
• Do not rely on a fan as your main cooling source when it’s really hot outside.
• Drink more water than usual and don’t wait until you’re thirsty to drink.
  • If your doctor limits the amount of fluids you drink or has you on water pills, ask them how much you should drink during hot weather.
• Don’t use the stove or oven to cook—it will make you and your house hotter.
• Wear loose, lightweight, light-colored clothing.
• Take cool showers or baths to cool down.
• Do not engage in very strenuous activities and get plenty of rest.
• Check on a friend or neighbor and have someone do the same for you.

Stay informed

• Check the local news for health and safety updates.
• Seek medical care immediately if you have, or someone you know has, symptoms of heat-related illness like muscle cramps, headaches, nausea or vomiting.

Caretaker checklist

Keep a close eye on those in your care by visiting them at least twice a day, and ask yourself these questions:

• Are they drinking enough water?
• Do they have access to air conditioning?
• Do they know how to keep cool?
• Do they show any signs of heat stress?

Infants and young children rely on others to keep them cool and hydrated when it’s hot outside.

Keep kids cool and hydrated

• Never leave infants or children in a parked car, even if the windows are open.
• Dress infants and children in loose, lightweight, light-colored clothing.
• Make sure they’re drinking plenty of fluids. Stay away from really cold drinks or drinks with too much sugar.

Never leave kids in a parked car

• Even when it feels cool outside, cars can heat up to dangerous temperatures very quickly.
• Leaving a window open is not enough- temperatures inside the car can rise almost 20 degrees Fahrenheit within the first 10 minutes, even with a window cracked open.
• Children who are left unattended in parked cars are at greatest risk for heat stroke, and possibly death.

Tips for traveling with children

• Never leave infants or children in a parked car, even if the windows are cracked open.
• To remind yourself that a child is in the car, keep a stuffed animal in the car seat. When the child is buckled in, place the stuffed animal in the front with the driver.
• When leaving your car, check to be sure everyone is out of the car. Do not overlook any children who have fallen asleep in the car.

Learn how to spot heat-related illness

• Seek medical care immediately if your child has symptoms of heat-related illness.

People who exercise in extreme heat are more likely to become dehydrated and get heat-related illness.

If you plan to exercise while it’s hot outside:

• Limit outdoor activity, especially during the middle of the day when the sun is hottest.
• Wear and reapply sunscreen as indicated on the package.
• Schedule workouts and practices earlier or later in the day when the temperature is cooler.
• Pace activity. Start activities slow and pick up the pace gradually.
• Drink more water than usual, and don’t wait until you’re thirsty to drink more. Muscle cramping may be an early sign of heat-related illness.
• Monitor a teammate’s condition, and have someone do the same for you.
• Wear loose, lightweight, light-colored clothing.

Learn how to spot heat-related illness

• Seek medical care immediately if you or a teammate has symptoms of heat-related illness.

WARNING!

If you feel faint or weak, STOP all activity and get to a cool place.

Extreme heat can be dangerous for anyone, but it can be especially dangerous for those with chronic medical conditions. If you or someone you know has a chronic medical condition, follow the information below to help keep you, or the person in your care, safe.

Why are people with chronic medical conditions more vulnerable to extreme heat?

• They may be less likely to sense and respond to changes in temperature.
• They may be taking medications that can make the effect of extreme heat worse.
• Conditions like heart disease, mental illness, poor blood circulation, and obesity* are risk factors for heat-related illness.
  • Individuals who are overweight or obese tend to retain more body heat.

Stay safe during extreme heat

• Keep in mind that heavy sweating can remove salt and minerals from your body. Talk to your doctor about how to safely replace salt and minerals lost through sweating.
• Do not engage in very strenuous activities and get plenty of rest.
• Check on a friend or neighbor, and have someone do the same for you.
• Check the local news for health and safety updates regularly.

Learn how to spot heat-related illness

• Seek medical care immediately if you or someone you know experiences symptoms of heat-related illness.

CARETAKER CHECKLIST

Keep a close eye on those in your care by visiting them at least twice a day, and ask yourself these questions:

• Are they drinking enough water?
• Do they have access to air conditioning?
• Do they know how to keep cool?
• Do they show any signs of heat stress?

Did you know that people who have diabetes—both type 1 and type 2—feel the heat more than people who don’t have diabetes? Some reasons why:

• Certain diabetes complications, such as damage to blood vessels and nerves, can affect your sweat glands so your body can’t cool as effectively. That can lead to heat exhaustion and heat stroke, which is a medical emergency.
• People with diabetes get dehydrated (lose too much water from their bodies) more quickly. Not drinking enough liquids can raise blood sugar, and high blood sugar can make you urinate more, causing dehydration. Some commonly used medicines like diuretics (“water pills” to treat high blood pressure) can dehydrate you, too.
• High temperatures can change how your body uses insulin. You may need to test your blood sugar more often and adjust your insulin dose and what you eat and drink.

It’s the Heat and the Humidity

Even when it doesn’t seem very hot outside, the combination of heat and humidity (moisture in the air) can be dangerous. When sweat evaporates (dries) on your skin, it removes heat and cools you. It’s harder to stay cool in high humidity because sweat can’t evaporate as well.

Whether you’re working out or just hanging out, it’s a good idea to check the heat index—a measurement that combines temperature and humidity. Take steps to stay cool (see sidebar) when it reaches 80°F in the shade with 40% humidity or above. Important to know: The heat index can be up to 15°F higher in full sunlight, so stick to the shade when the weather warms up.

Physical activity is key to managing diabetes, but don’t get active outdoors during the hottest part of the day or when the heat index is high. Get out early in the morning or in the evening when temperatures are lower, or go to an air-conditioned mall or gym to get active.

Your Blood Sugar Knows Best

Kids out of school, vacations, get-togethers, family reunions. The summer season can throw off your routine, and possibly your diabetes management plan. Check your blood sugar more often to make sure it’s in your target range no matter what the summer brings. It’s especially important to recognize what low blood sugar feels like and treat it as soon as possible.

Warm-weather wisdom:

• Drink plenty of water—even if you’re not thirsty—so you don’t get dehydrated.
• Avoid alcohol and drinks with caffeine, like coffee and energy or sports drinks. They can lead to water loss and spike your blood sugar levels.
• Check your blood sugar before, during, and after you’re active. You may need to change how much insulin you use. Ask your doctor if you would like help in adjusting your dosage.
• Wear loose-fitting, lightweight, light-colored clothing.
• Wear sunscreen and a hat when you’re outside. Sunburn can raise your blood sugar levels.
• Don’t go barefoot, even on the beach or at the pool.
• Use your air conditioner or go to an air-conditioned building or mall to stay cool. In very high heat, a room fan won’t cool you enough.

Too Hot to Handle

Know what else feels the heat? Diabetes medicines, supplies, and equipment:

• Don’t store insulin or oral diabetes medicine in direct sunlight or in a hot car. Check package information about how high temperatures can affect insulin and other medicines.
• If you’re traveling, keep insulin and other medicines in a cooler. Don’t put insulin directly on ice or on a gel pack.
• Heat can damage your blood sugar monitor, insulin pump, and other diabetes equipment. Don’t leave them in a hot car, by a pool, in direct sunlight, or on the beach. The same goes for supplies such as test strips.

But don’t let the summer heat stop you from taking your diabetes medicine and supplies with you when you’re out and about. You’ll need to be able to test your blood sugar and take steps if it’s too high or too low. Just make sure to protect your diabetes gear from the heat.

Stormy Weather

June 1 marked the beginning of hurricane season. Severe thunderstorms with hail, high winds, and tornadoes are more likely in warm weather, too. People with diabetes face extra challenges if a strong storm knocks out the power or they have to seek shelter away from home. Plan how you’ll handle medicine that needs refrigeration, such as insulin. And be prepared by packing an emergency go-bag—a supply kit you can grab quickly if you need to leave your home.

Here’s to staying cool, staying safe, and enjoying the long summer days!

Your Summer Checklist

• Drink plenty of water.
• Test your blood sugar often.
• Keep medicines, supplies, and equipment out of the heat.
• Stay inside in air-conditioning when it’s hottest.
• Wear loose, light clothing.
• Get medical attention for heat-related illness.
• Make a plan in case you lose power.
• Have a go-bag ready for emergencies.

Prepare ahead of time for extreme heat this summer, especially if air conditioning is not available in your home.

Stay cool, stay hydrated

• If available, use air conditioning to keep your home cool.
• Drink more water than usual, and don’t wait until you’re thirsty to drink.
• Use a buddy system- check on a friend or neighbor, and have someone do the same for you.

If air conditioning is not available in your home:

• Contact Low Income Home Energy Assistance Program (LIHEAP) for help.
• Contact your local health department or locate an air-conditioned shelter in your area.
• Spend some time at a shopping mall or public library- even a few hours spent in air conditioning can help.
• Take cool showers or baths.
• Don’t rely solely on fans to keep you cool. While electric fans might provide some comfort, when temperatures are really hot, they won’t prevent heat-related illness.
• Use your stove and oven less to maintain a cooler temperature in your home.

Learn how to spot heat-related illness

• Seek medical care immediately if you have, or someone you know has, symptoms of heat-related illness like muscle cramps, headaches, nausea or vomiting.

People who work outdoors are more likely to become dehydrated and get heat-related illness.

If you have to work while it’s hot outside:

• Prevent heat illness with acclimatization.
• Drink plenty of water, and don’t wait until you are thirsty to drink.
• Avoid alcohol or liquids containing large amounts of sugar.
• Wear and reapply sunscreen as indicated on the package.
• Ask if tasks can be scheduled for earlier or later in the day to avoid midday heat.
• Wear a brimmed hat and loose, lightweight, light-colored clothing.
• Spend time in air-conditioned buildings during breaks and after work.
• Encourage co-workers to take breaks to cool off and drink water.

Learn how to spot heat-related illness

• Seek medical care immediately if you or a co-worker has symptoms of heat-related illness.

WARNING!

If you feel faint or weak, STOP all activity and get to a cool place.

Keep your pets safe

• Never leave your pet in a parked car- they can suffer from heat-related illness too!
• Provide plenty of fresh water for your pets, and leave the water in a shady area.

Never leave pets in a parked car

• Even in cool temperatures, cars can heat up to dangerous temperatures very quickly.
• Leaving a window open is not enough- temperatures inside the car can rise almost 20 degrees Fahrenheit within the first 10 minutes, even with a window cracked open.

After a long winter cooped up, the arrival of sunny days can make you eager to be outside. Getting outdoors can be good for you in many ways. It provides opportunities for exercise. It can also boost your mental health.

But as the heat rises, some health risks also increase. Intense heat can put strain on both your body and brain. Too much heat can cause a heat-related illness called hyperthermia. Mild hyperthermia can cause discomfort, like muscle cramps or swelling in the ankles and feet.

Heat exhaustion is more serious. It occurs when your body can no longer keep itself cool. You may start to feel dizzy or nauseated. Other symptoms include feeling thirsty, weak, or uncoordinated.

The most extreme form of hyperthermia is heat stroke. Heat stroke is life-threatening, so seek medical help right away. Symptoms include fainting or having trouble walking. You may start feeling confused or agitated. You can also feel very hot but not sweat or have dry, flushed skin.

Some people are more at risk for heat-related illness than others. That includes infants and young children, and those with certain health conditions, such as heart, lung, or kidney disease. Older adults are the most heat sensitive. That’s because the body’s ability to cool itself changes as we get older.

There are two main ways your body regulates its temperature, explains Dr. Craig Crandall, who studies heat effects on the body at UT Southwestern Medical Center. “One is increasing how much blood flows to the skin. The other is how much we sweat.”

Neither of these works as well in older adults, Crandall says. That makes it more difficult for them to cool off. His research has shown that sitting in front of a fan increased older adults’ body temperature in extreme heat. That’s because they weren’t sufficiently sweating when the hot air was blowing over their skin. This suggests that older adults may need to use other ways to keep cool, such as going to an air-conditioned place.

Too much heat is not safe for anyone. If you’re outside in the heat, drink lots of water. Don’t try to exercise or do a lot of activities outdoors when it’s hot.

If you start to feel sick in the heat, rest in a cool place and drink plenty of fluids. If you think someone has heat stroke, get them to a cool place and call 911.

“Shade is your friend,” Crandall says. “If you’re going out to exercise or mow the lawn, take breaks in the shade.”

If possible, go into an air-conditioned room for a while. “That time you’re inside, your core temperature is going to be cooled,” Crandall explains. “If you stay outside, it may just go up and up and up.”

If you want to exercise outside in the summer, start slow. “It takes about 10 days to two weeks to get acclimated to hotter temperatures,” Crandall says.

Heat isn’t the only hazard during the summer. It’s also important to protect your skin and your eyes from the sun. See the Wise Choices box for tips to keep safe in the heat.

Protect Yourself From the Heat and Sun

• Do outdoor activities during the coolest part of the day, in the early morning or evening.
• Exercise in an air-conditioned space if possible. Or do water workouts.
• Try to stay in the shade when outdoors during peak sunlight.
• Drink plenty of liquids, especially water. Avoid drinks that contain alcohol or caffeine.
• Wear protective clothing, such as hats, long-sleeve shirts, and long pants to block out the sun’s harmful rays. Choose light-colored, loose-fitting clothing.
• Use sunscreen that blocks both UVA and UVB radiation. Choose a sun protection factor (SPF) of at least 15, preferably 30. Reapply frequently.
• Use sunglasses that block both UVA and UVB.
• If you don’t have air conditioning, keep your home as cool as possible. If you need help paying energy bills, visit go.usa.gov/x6arw or call 1-866-674-6327.

Learn about heat-related illness and how to stay cool and safe in hot weather.

High temperatures kill hundreds of people every year. Heat-related deaths and illness are preventable, yet more than 700 people die from extreme heat every year in the United States.

Take measures to stay cool, stay hydrated, and stay informed. Getting too hot can make you sick. You can become ill from the heat if your body can’t compensate for it and properly cool you off. The main things affecting your body’s ability to cool itself during extremely hot weather are:

• High humidity. When the humidity is high, sweat won’t evaporate as quickly. This keeps your body from releasing heat as fast as it may need to.
• Personal factors. Age, obesity, fever, dehydration, heart disease, mental illness, poor circulation, sunburn, and prescription drug and alcohol use all can play a role in whether a person can cool off enough in very hot weather.

Those who are at highest risk include people 65 and older, children younger than two, and people with chronic diseases or mental illness.

Closely monitor people who depend on you for their care and ask these questions:

• Are they drinking enough water?
• Do they have access to air conditioning?
• Do they need help keeping cool?

People at greatest risk for heat-related illness can take the following protective actions to prevent illness or death:

• Stay in air-conditioned buildings as much as you can. Air-conditioning is the number one way to protect yourself against heat-related illness and death. If your home is not air-conditioned, reduce your risk for heat-related illness by spending time in public facilities that are air-conditioned and using air conditioning in vehicles. Contact your local health department or locate an air-conditioned shelter in your area.
• Do not rely on a fan as your main cooling device during an extreme heat event.
• Drink more water than usual, and don’t wait until you’re thirsty to drink.
• Check on friends and neighbors and have someone check on you.
• Limit use of the stove and oven—it will make you and your house hotter.

Even young and healthy people can get sick from the heat if they participate in strenuous physical activities during hot weather:

• Limit your outdoor activity, especially midday when the sun is hottest.
• Pace yourself. Start activities slowly and pick up the pace gradually.
• Drink more water than usual, and don’t wait until you’re thirsty to drink more. Muscle cramping may be an early sign of heat-related illness.
• Wear lightweight, loose-fitting clothing.

If you play a sport that practices during hot weather, protect yourself and look out for your teammates:

• Schedule workouts and practices earlier or later in the day when the temperature is cooler.
• Monitor a teammate’s condition and have someone do the same for you.
• Seek medical care right away if you or a teammate has symptoms of heat-related illness.

Everyone should take these steps to prevent heat-related illnesses, injuries, and death during hot weather:

• Stay in an air-conditioned indoor location as much as you can.
• Drink plenty of fluids even if you don’t feel thirsty.
• Schedule outdoor activities carefully.
  • Wear lightweight, loose-fitting clothing and sunscreen.
  • Pace yourself.
• Take cool showers or baths to cool down.
• Check on friends and neighbors and have someone check on you.
• Never leave children or pets in cars.
• Check the local news for health and safety updates.

Stay Cool

Wear Appropriate Clothing: Choose lightweight, light-colored, loose-fitting clothing.

Stay Cool Indoors: Stay in an air-conditioned place as much as possible. If your home does not have air conditioning, go to the shopping mall or public library—even a few hours spent in air conditioning can help your body stay cooler when you go back into the heat. Call your local health department to see if there are any heat-relief shelters in your area.

• Keep in mind: Electric fans may provide comfort, but when the temperature is in the high 90s, they will not prevent heat-related illness. Taking a cool shower or bath or moving to an air-conditioned place is a much better way to cool off. Use your stove and oven less to maintain a cooler temperature in your home.

Schedule Outdoor Activities Carefully: Try to limit your outdoor activity to when it’s coolest, like morning and evening hours. Rest often in shady areas so that your body has a chance to recover.

Pace Yourself: Cut down on exercise during the heat. If you’re not accustomed to working or exercising in a hot environment, start slowly and pick up the pace gradually. If exertion in the heat makes your heart pound and leaves you gasping for breath, STOP all activity. Get into a cool area or into the shade, and rest, especially if you become lightheaded, confused, weak, or faint.

Wear Sunscreen: Sunburn affects your body’s ability to cool down and can make you dehydrated. If you must go outdoors, protect yourself from the sun by wearing a wide-brimmed hat, sunglasses, and by putting on sunscreen of SPF 15 or higher 30 minutes prior to going out. Continue to reapply it according to the package directions.

• Tip: Look for sunscreens that say “broad spectrum” or “UVA/UVB protection” on their labels- these products work best.

Do Not Leave Children in Cars: Cars can quickly heat up to dangerous temperatures, even with a window cracked open. While anyone left in a parked car is at risk, children are especially at risk of getting a heat stroke or dying. When traveling with children, remember to do the following:

• Never leave infants, children or pets in a parked car, even if the windows are cracked open.
• To remind yourself that a child is in the car, keep a stuffed animal in the car seat. When the child is buckled in, place the stuffed animal in the front with the driver.
• When leaving your car, check to be sure everyone is out of the car. Do not overlook any children who have fallen asleep in the car.

Avoid Hot and Heavy Meals: They add heat to your body!

Stay Hydrated

Drink Plenty of Fluids: Drink more fluids, regardless of how active you are. Don’t wait until you’re thirsty to drink.

• Warning: If your doctor limits the amount you drink or has you on water pills, ask how much you should drink while the weather is hot.
• Stay away from very sugary or alcoholic drinks—these actually cause you to lose more body fluid. Also avoid very cold drinks, because they can cause stomach cramps.

Replace Salt and Minerals: Heavy sweating removes salt and minerals from the body that need to be replaced. A sports drink can replace the salt and minerals you lose in sweat.

• If you are on a low-salt diet, have diabetes, high blood pressure, or other chronic conditions, talk with your doctor before drinking a sports beverage or taking salt tablets.

Keep Your Pets Hydrated: Provide plenty of fresh water for your pets, and leave the water in a shady area.

Stay Informed

Check for Updates: Check your local news for extreme heat alerts and safety tips and to learn about any cooling shelters in your area.

Know the Signs: Learn the signs and symptoms of heat-related illnesses and how to treat them.

Use a Buddy System: When working in the heat, monitor the condition of your co-workers and have someone do the same for you. Heat-induced illness can cause a person to become confused or lose consciousness. If you are 65 years of age or older, have a friend or relative call to check on you twice a day during a heat wave. If you know someone in this age group, check on them at least twice a day.

Monitor Those at High Risk: Although anyone at any time can suffer from heat-related illness, some people are at greater risk than others:

• Infants and young children
• People 65 years of age or older
• People who are overweight
• People who overexert during work or exercise
• People who are physically ill, especially with heart disease or high blood pressure, or who take certain medications, such as for depression, insomnia, or poor circulation

Visit adults at risk at least twice a day and closely watch them for signs of heat exhaustion or heat stroke. Infants and young children, of course, need much more frequent watching.