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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• What is hypothermia?
• What causes hypothermia?
• What are the risk factors for hypothermia?
• What are the signs and symptoms of hypothermia?
• How is hypothermia diagnosed?
• How is hypothermia treated?
• When should I call the doctor for hypothermia?
• Can hypothermia be prevented?
• Hypothermia At A Glance
• Patient Comments: Hypothermia - Symptoms
• Find a local Doctor in your town
• Hypothermia Index

The body starts to slow as the temperature drops. Aside from the cold that is felt and the shivering that may occur, mental function is most affected initially. A particular danger of hypothermia is that it develops gradually, and since it affects thinking and reasoning, it may go unnoticed.

• Initial hunger and nausea will give way to apathy as the core body temperature drops.
  
  
• This is followed by confusion, lethargy, slurred speech, loss of consciousness, and coma.
  
  
• Often the affected person will lie down, fall asleep, and die. In some cases, the patient will paradoxically remove their clothes just before this occurs.

The decrease in brain function occurs in direct relationship to the decrease in body temperature (the colder the body, the less the brain function). Brain function stops at a core temperature of 68 F (20 C).

The heart is subject to abnormal electrical rhythms as hypothermia progresses. Ventricular fibrillation, a disorganized rhythm in which the heart is unable to pump, may occur at core temperatures below 82.4 F (28 C). This is one type of cardiac arrest.