Hypothermia is a condition where the body’s core temperature drops below 95°F (35°C). This can occur when the body is exposed to cold temperatures for an extended period, or when it loses more heat than it generates. While most cases of hypothermia occur at very cold temperatures, the condition can affect you even in cooler temperatures over 40 F (4.4 C) if you become chilled from sweat, rain, or submersion in cold water. In the US, most cases of hypothermia or excessive cold occur in rural areas.
Causes include prolonged exposure to cold temperatures, wet clothing or submersion in cold water, lack of adequate clothing or shelter, alcohol or drug intoxication or certain medical conditions such as hypoglycemia or hypothyroidism. Symptoms include shivering, confusion, slowed heart rate and breathing, slurred speech, fumbling hands or loss of coordination, drowsiness, and coma. If left untreated, hypothermia can lead to cardiac arrest, liver damage, kidney failure, coma, and death.
Hypothermia risk factors include substance use disorders (including alcohol use disorder), homelessness, any condition that affects judgment (such as hypoglycemia), the extremes of age (including infants and children) poor clothing, chronic medical conditions (such as hypothyroidism and sepsis), and living in a cold environment. Hypothermia occurs frequently in major trauma and is observed in severe cases of anorexia nervosa. Hypothermia is also associated with worse outcomes in people with sepsis— while most people with sepsis develop fevers (elevated body temperature), some develop hypothermia.
If you or someone you know has symptoms of hypothermia, and a low body temperature, you should call 911 or go to the emergency room immediately. Hypothermia is a medical emergency and should be treated as soon as possible—get medical help immediately. In the meantime, you should:
- Get somewhere warm and dry.
- Take off wet clothes and replace them with dry clothes.
- Wrap up in a warm blanket, hat, socks, and coat.
- Drink warm liquids.
How do you prevent hypothermia?
- Dress in layers: Wearing multiple layers of loose clothing is warmer than one thick layer. The layers create an insulating air gap that keeps you warm.
- Cover your head, hands, and feet: A hat reduces heat loss from your head, which accounts for about 30% of body heat loss. Wear gloves and waterproof, insulated boots. Children lose proportionally more heat through their heads. Hoods and hats are more important to children because of this.
- Stay active: Stay active to maintain body heat but avoid activities that cause you to sweat.
- Stay dry: Change out of wet clothes as soon as possible.
- Drink fluids: Drink plenty of warm, non-alcoholic, and decaffeinated fluids.
- Avoid alcohol, caffeine, and nicotine: These substances cause heat loss.
- Be aware of wind chill: Take wind chill into account when dressing.
- Take breaks: Take frequent breaks from the cold.
- Avoid cold water: Avoid activities in or near cold water unless you can get help quickly.
- Know your medications: Ask your doctor if you take any medications that affect your ability to maintain body temperature.
- Get out of the cold: If you have signs of hypothermia or frostbite, get out of the cold immediately.
Sources: Medscape, Cleveland Clinic, CDC
