Printer Logo

Hypothermia

Exercise - dress appropriately
Skin layers

Definition

Hypothermia is dangerously low body temperature, below 95°F (35°C).

Alternative Names

Low body temperature; Cold exposure; Exposure

Considerations

Other types of cold injuries that affect the limbs are called peripheral cold injuries. Of these, frostbite is the most common freezing injury. Nonfreezing injuries that occur from exposure to cold wet conditions include trench foot and immersion foot conditions. Chilblains (also known as pernio) are small, itchy or painful lumps on the skin that often occur on the fingers, ears, or toes. They are a type of nonfreezing injury that develops in cold, dry conditions.

You are more likely to develop hypothermia if you are:

Causes

Hypothermia occurs when more heat is lost than the body can make. In most cases, it occurs after long periods in the cold.

Common causes include:

Symptoms

As a person develops hypothermia, they slowly lose the ability to think and move. In fact, they may even be unaware that they need emergency treatment. Someone with hypothermia also is likely to have frostbite.

The symptoms include:

Lethargy, cardiac arrest, shock, and coma can set in without prompt treatment. Hypothermia can be fatal.

First Aid

Take the following steps if you think someone has hypothermia:

  1. If the person has any symptoms of hypothermia that are present, especially confusion or problems thinking, call 911 right away.
  2. If the person is unconscious, check airway, breathing, and circulation. If necessary, begin rescue breathing or CPR. If the victim is breathing fewer than 6 breaths per minute, begin rescue breathing.
  3. Take the person inside to room temperature and cover with warm blankets. If going indoors is not possible, get the person out of the wind and use a blanket to provide insulation from the cold ground. Cover the person's head and neck to help retain body heat.
  4. Victims of severe hypothermia should be removed from the cold environment with as little exertion as possible. This helps to avoid warmth from being shunted from the person's core to the muscles. In a very mildly hypothermic person, muscular exercise is thought to be safe, however.
  5. Once inside, remove any wet or tight clothes and replace them with dry clothing.
  6. Warm the person. If necessary, use your own body heat to aid the warming. Apply warm compresses to the neck, chest wall, and groin. If the person is alert and can easily swallow, give warm, sweetened, nonalcoholic fluids to aid the warming.
  7. Stay with the person until medical help arrives.

Do Not

Follow these precautions:

When to Contact a Medical Professional

Call 911 anytime you suspect someone has hypothermia. Give first aid while waiting for emergency help.

Prevention

Before you spend time outside in the cold, DO NOT drink alcohol or smoke. Drink plenty of fluids and get enough food and rest.

Wear proper clothing in cold temperatures to protect your body. These include:

Avoid:

References

Giesbrecht GG. Cold stress, near drowning and accidental hypothermia: a review. Aviat Space Environ Med. 2000;71(7):733-752. PMID: 10902937 www.ncbi.nlm.nih.gov/pubmed/10902937.

Sawka MN, O'Connor FG. Disorders due to heat and cold. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 109.

Zafren K, Danzl DF. Frostbite and nonfreezing cold injuries. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 131.

Zafren K, Danzl DF. Accidental hypothermia. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 132.


Review Date: 10/16/2017
Reviewed By: Jesse Borke, MD, FACEP, FAAEM, Attending Physician at FDR Medical Services/Millard Fillmore Suburban Hospital, Buffalo, NY. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.