Low Body Temperature (Hypothermia)

What is hypothermia?

Hypothermia is a dangerously low body temperature. Normal body temperature ranges from 97.2 to 99.5°F (36.2 to 37.5°C). If your body temperature is just a few degrees lower than this, your bodily functions slow down. If your temperature drops too low and stays low for more than a few hours, the body's organs can be damaged and there is a risk of death.

How does it occur?

Your temperature can drop gradually as your body is exposed to cold temperatures. This could happen if:

• You spend a lot of time in a cold, unheated indoor environment.
• You are outside in cold weather without proper protection against the cold, wind, rain, or snow.
• You wear cold, wet clothing for too long.

Your temperature can drop very quickly if you fall into freezing, cold water.

Hypothermia is more likely to happen in a cool or cold environment if something, such as an injury, keeps you from moving or being alert. Hypothermia may happen after a heart attack or stroke if you don’t receive prompt treatment.

Babies, small children, and older adults are more likely to have hypothermia. They may get it even when they are indoors. The very young and the very old use up energy reserves quickly, so it is harder for them to keep a normal body temperature in cool or cold surroundings. Other factors, such as poorly heated homes and poor nutrition, also put older adults at risk for hypothermia.

Other factors that increase the risk of hypothermia are alcohol use, drug abuse, or chronic medical problems with the circulatory system, nervous system, or thyroid gland.

What are the symptoms?

Hypothermia usually occurs gradually. The symptoms progress as follows:

• cold feet, hands, and face
• shivering (older adults may not have this symptom)
• fatigue
• drowsiness
• confusion, irrational thinking
• irritable attitude
• cold skin on the chest and abdomen
• poor coordination and balance
• stiff, jerking movements
• slow, shallow breathing
• slowed or irregular heartbeat
• stiff muscles and some trembling
• loss of consciousness
• loss of heartbeat, leading to death.

How is it diagnosed?

The diagnosis is based on where you have been and your symptoms. The healthcare provider will check for shivering, confusion, or other symptoms of hypothermia. Your body temperature is checked and will usually be less than 96°F.

How is it treated?

Hypothermia is a medical emergency and needs to be treated right away. Get emergency help right away or call 911.

If you are with someone who is hypothermic, here's what you can do to try to help while you wait for medical help:

• If the person is not breathing or has no pulse, start rescue breathing (CPR).
• If the person is breathing:
  • Take off cold, wet clothing.
  • Wrap the person in blankets or other dry coverings (warm the blankets, if possible). If you must remain outdoors, cover the person's head (but not the face) and keep him or her from direct contact with the cold ground.
  • As soon as possible, move the person carefully to a warm place and begin rewarming.

Rewarming must be done slowly to prevent a rush of blood to the surface of the body away from vital organs that need blood. If rewarming cannot be done by trained medical personnel, do the following:

• Remove any damp clothes and dress the person in dry clothes or cover the person lightly with blankets.
• Give warm liquids to drink if the person is alert and not in danger of choking.
• Allow the person to warm up gradually in a warm room.
• Give the person a warm (NOT hot) bath.

When you are caring for someone who is hypothermic:

• Don’t give the person hot liquids to drink.
• Don’t force the person to eat or drink anything.
• Don’t give alcoholic beverages.
• Don’t try to warm cold skin by rubbing or massaging.
• Don’t cover the person with heavy layers of blankets.
• Don’t allow the person to walk.
• Don’t use hot water bottles, heating pads, or electric blankets.

Someone who has severe hypothermia needs to be treated in a hospital as soon as possible.

How long will the effects of hypothermia last?

How long the effects of hypothermia last depends on how badly the body organs were damaged. In many cases you will recover in 3 to 12 hours with treatment. In severe cases, hypothermia can cause death.

How can I help prevent hypothermia?

The best way to prevent hypothermia is to be prepared and dress appropriately. Wear several layers of clothes rather than a single, thick layer. The best layers are those that provide good insulation and keep moisture away from the skin. Materials that do this include polypropylene, polyesters, and wool. Wear an outer garment that is waterproof but will also "breathe." Wear a hat and keep your neck covered to help retain body heat.

Hypothermia can occur when you least expect it. Follow these safety guidelines:

• Be prepared for a sudden change in the weather. On outings, carry proper clothing and emergency supplies in a backpack so you are prepared for bad weather.
• Don’t begin an outing too late in the day.
• Take off clothing when it gets wet and put on warm, dry clothes.
• Drink plenty of nonalcoholic fluids. People who get hypothermia are often dehydrated.
• Know the symptoms of hypothermia and the emergency treatment for it.
• Keep space blankets (sheets of plastic and aluminum that help retain heat) and high-energy food handy in case of an emergency.

If you are over age 65, you should take the following precautions during cold weather:

• Have someone check on you regularly during the winter. You should be checked at least once a day if it is very cold.
• Have your home properly insulated.
• Keep your living area warm (above 65°F, or 18.3°C).
• Wear layers of warm clothing to help keep your body temperature even. Cover your head and neck, even indoors, if you have trouble keeping warm.
• Stay dry.
• Be sure to have and use enough warm blankets.
• Practice good general health habits, such as getting plenty of rest, exercising, and eating nutritious food.
• Keep a supply of nutritious food on hand that can be prepared easily. Eat hot meals and drink warm liquids throughout the day. Arrange for meals to be brought to your home if you are unable to cook.
• Avoid alcoholic drinks.
• Ask your healthcare provider if any medicine you take might increase your risk of hypothermia. (Drugs that reduce the body's ability to respond to cold include tranquilizers, some cardiovascular drugs, sedatives, and antidepressants.)
• Take your temperature occasionally. If your temperature with your mouth thermometer is less than 97 degrees, call a relative or friend to come check on you and the temperature of your house. You may need to stay in a warmer environment until the outside temperature warms up.
• Ask for help whenever needed from agencies such as the Visiting Nurses Association, agencies that can provide funds to help pay fuel bills, the Council on Aging, churches, or hospitals.