Cold weather can affect your body in different ways. You can get frostbite, which is an injury to the body that is caused by freezing. Your body can also lose heat faster than you can produce it. That can cause hypothermia, or abnormally low body temperature. It can make you sleepy, confused, and clumsy. Because it happens gradually and affects your thinking, you may not realize you need help. That makes it especially dangerous. A body temperature below 95° F is a medical emergency and can lead to death if not treated promptly.

Anyone who spends much time outdoors in cold weather can get hypothermia. You can also get it from being cold and wet, or under cold water for too long. Babies and old people are especially at risk. Babies can get it from sleeping in a cold room.

• Hypothermia is caused by prolonged exposures to very cold temperatures. When exposed to cold temperatures, your body begins to lose heat faster than it’s produced. Lengthy exposures will eventually use up your body’s stored energy, which leads to lower body temperature.
• Body temperature that is too low affects the brain, making the victim unable to think clearly or move well. This makes hypothermia especially dangerous, because a person may not know that it’s happening and won’t be able to do anything about it.
• While hypothermia is most likely at very cold temperatures, it can occur even at cool temperatures (above 40°F) if a person becomes chilled from rain, sweat, or submersion in cold water.

The body continuously engages in coordinated physiological processes to maintain a stable temperature. In some cases, however, overriding this system can be useful, or even life-saving. Hypothermia is the clinical term for an abnormally low body temperature (hypo- = “below” or “under”). Controlled hypothermia is clinically induced hypothermia performed in order to reduce the metabolic rate of an organ or of a person’s entire body.

Controlled hypothermia often is used, for example, during open-heart surgery because it decreases the metabolic needs of the brain, heart, and other organs, reducing the risk of damage to them. When controlled hypothermia is used clinically, the patient is given medication to prevent shivering. The body is then cooled to 25–32°C (79–89°F). The heart is stopped and an external heart-lung pump maintains circulation to the patient’s body. The heart is cooled further and is maintained at a temperature below 15°C (60°F) for the duration of the surgery. This very cold temperature helps the heart muscle to tolerate its lack of blood supply during the surgery.

Some emergency department physicians use controlled hypothermia to reduce damage to the heart in patients who have suffered a cardiac arrest. In the emergency department, the physician induces coma and lowers the patient’s body temperature to approximately 91 degrees. This condition, which is maintained for 24 hours, slows the patient’s metabolic rate. Because the patient’s organs require less blood to function, the heart’s workload is reduced.

Victims of hypothermia are often:

• Older adults with inadequate food, clothing, or heating
• Babies sleeping in cold bedrooms
• People who remain outdoors for long periods—the homeless, hikers, hunters, etc.
• People who drink alcohol or use illicit drugs.

Cold temperatures can cause hypothermia, which occurs when body temperature drops below 95 degrees Fahrenheit. Warning signs include shivering, exhaustion, confusion, memory loss, and fumbling hands. Infants and older adults are especially at risk for hypothermia, as they have a harder time regulating their body temperature. Medical conditions in older adults can also make that problem worse. Hypothermia can lead to health problems like heart attacks, kidney problems, liver damage, or death.  

Even a small drop in temperature or a short time spent outside can cause a large drop in body temperature in infants and older adults. And according to the National Institute on Aging, living in a poorly heated home can cause hypothermia. To avoid developing hypothermia indoors, place a rolled towel in front of doors to keep out drafts, make sure windows are weather stripped or caulked if they have gaps, and keep indoor temperatures above 68 degrees Fahrenheit.  

The following are warnings signs of hypothermia:

Adults:

• Shivering
• Exhaustion or feeling very tired
• Confusion
• Fumbling hands
• Memory loss
• Slurred speech
• Drowsiness

Babies:

• bright red, cold skin
• very low energy

Symptoms of hypothermia can vary depending on how long you have been exposed to the cold temperatures.

Early Symptoms

• Shivering
• Fatigue
• Loss of coordination
• Confusion and disorientation

Late Symptoms

• No shivering
• Blue skin
• Dilated pupils
• Slowed pulse and breathing
• Loss of consciousness

Hypothermia is a medical emergency. If you notice any of the above signs, take the person’s temperature. If it is below 95° F, get medical attention immediately!

If you are not able to get medical help right away, try to warm the person up.

• Get the person into a warm room or shelter.
• Remove any wet clothing the person is wearing.
• Warm the center of the person’s body—chest, neck, head, and groin—using an electric blanket, if available. You can also use skin-to-skin contact under loose, dry layers of blankets, clothing, towels, or sheets.
• Warm drinks can help increase body temperature, but do not give alcoholic drinks. Do not try to give beverages to an unconscious person.
• After body temperature has increased, keep the person dry and wrap their body, including their head and neck, in a warm blanket.
• Get the person proper medical attention as soon as possible.

A person with severe hypothermia may be unconscious and may not seem to have a pulse or to be breathing. In this case, handle the person gently, and get emergency assistance immediately.

• Perform CPR, even if the person appears dead. CPR should continue until the person responds or medical aid becomes available. Keep warming the person while performing CPR. In some cases, hypothermia victims who appear to be dead can be successfully resuscitated.

To avoid hypothermia or frostbite when going outside: 

• Dress in layers 
• Wear warm clothing to protect your hands, feet, neck and face 
• Get plenty of food and fluids 
• Avoid alcoholic drinks 

To prepare your car for a cold-weather emergency 

Make sure to have an emergency car kit with supplies like: 

• Extra warm clothing and blankets  
• An ice scraper 
• A snow shovel 
• Cat litter or sand to help tires grip on snow and ice 
• Water and non-perishable food 
• Jumper cables 
• First aid kit with any necessary medicines and a pocketknife 
• A battery-powered radio, a flashlight, and extra batteries 
• Emergency flares or distress flags 
• Waterproof matches and a can to melt snow for water 

To prepare your home for a cold-weather emergency 

Make a disaster plan and prep your home for any winter weather by doing the following: 

• Make sure you have important phone numbers – such as for your doctor and pharmacy – written down 
• Prepare your home to keep out the cold with insulation, caulking, and weather stripping 
• Gather supplies in case you need to stay home for several days without power 
• If you plan to use your fireplace or wood stove for emergency heating, have your chimney or flue inspected each year 

Taking a first aid or emergency resuscitation (CPR) course is a good way to prepare for health problems related to cold weather. Knowing what to do is an important part of protecting your health and the health of others.

Being prepared is your best defense against having to deal with extremely cold weather. By preparing your home and car ahead of winter storms or other winter emergencies, and by taking safety precautions during extremely cold weather, you can reduce your risk of developing health problems related to cold weather.