Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at March 29, 2016

A healthy person’s body temperature is 98.6 degrees Fahrenheit (37 degrees Celsius). When it rises above this level, the person is most likely suffering from a fever. When body temperature drops and reaches a level below 95 degrees Fahrenheit (35 degrees Celsius) the person is most likely suffering from a condition called hypothermia.


Definition & Facts

Hypothermia usually results from cold conditions when the body starts losing heat more quickly that it can produce warmth, causing the body temperature to drop. The longer a person is exposed to severe cold conditions, the more the body temperature drops and the more likely they are to develop hypothermia.

When the body temperature is between 95 degrees Fahrenheit (36 degrees Celisus) and 89 degrees Fahrenheit (31.6C), the hypothermia is considered mild. From 89 degrees Fahrenheit (31.6 degrees Celsius) to 82 degrees Fahrenheit (27.8 degrees Celsius) it is considered moderate. A body temperature lower than 82 degrees Fahrenheit (27.8 degrees Celsius) is considered severe.

Unless the condition is treated, hypothermia can lead to the heart, lungs, and central nervous systems shutting down and cause death. Older people are more susceptible to hypothermia because the body’s ability to regulate body temperature decreases with age. Children can be affected as well. Infants’ bodies have reduced ability to deal with the cold and they cannot communicate their pain verbally.

Symptoms & Complaints

Initial symptoms of mild hypothermia are:

  • Shivering, which means the body is trying to generate warmth
  • Confusion, which is often indicated by a person having trouble speaking, showing decreased coordination and experiencing dizziness
  • Fatigue, fast breathing, and a heart rate that is higher than usual.

As the body temperature continues to drop and more severe hypothermia sets in, shivering usually stops while other symptoms become worse. A slow pulse, slow breathing, slurred speech, and more clumsiness and confusion are typical. In severe conditions, breathing can stop. Infants with hypothermia are characterized by a cold skin that is bright red. The infant’s energy becomes lower and their cries become weaker.


Hypothermia most often results from exposure to cold temperatures such as being immersed for an extended period of time in exceptionally cold water as in an accidental fall from a boat. Another common cause is being exposed to extreme cold while outside for too long and being inadequately dressed for the weather.

On rare occasions, the weather is so cold or the wind so strong that a person who is exposed to these conditions for even a fairly short time cannot escape hypothermia no matter how warmly dressed they are. Hypothermia also can result when older people or infants are exposed to lower temperatures in a badly heated home or following a power outage.

The risk increases if the person has diabetes, takes certain medications or uses drugs or alcohol. Those who are mentally impaired also might be unaware of the risk they are taking in cold weather.

Diagnosis & Tests

When body temperature drops, the brain slows down, as does breathing and the heart rate. Hypothermia is usually diagnosed through the physical signs that result, such as disorientation, confusion and slurred speech.

Sometimes these signs, specially if the hypothermia is mild, are not interpreted as being hypothermia, particularly in the elderly and infants, where the symptoms may be attributed to other causes, such as dementia in the elderly.

In severe cases of hypothermia, fatigue and greater confusion can result, causing a person to make bad decisions and, in some cases, endangering them even more. The best check is through the use of a specialized thermometer, if one is available, which will indicate that the person’s body temperature has dropped significantly below the normal level. In other cases, blood tests can help to affirm that the individual has hypothermia and just how severe it is due to its effects on other organs and body processes.

Treatment & Therapy

Should a person shows signs of hypothermia or they have had prolonged exposure to extreme cold weather or exceptionally cold water, one should call 911. While waiting for the emergency services to arrive, the following steps may be taken:

  • Remove the cause of the cold temperature. Usually this means taking the person inside or, if this is not possible, to a location that is warm and dry.
  • If they cannot be moved out of the cold, try to provide some sort of shelter from the wind.
  • Cover a hypothermia sufferer with blankets or warm clothing. The head should be covered, but the face left exposed.
  • If the person is lying on a cold surface, place a blanket or coat on the ground to reduce the amount of cold reaching the body.
  • Wet clothing should be removed from those who have been immersed in cold water.
  • It is advisable to be gentle when treating a person suffering from severe hypothermia. Avoid massaging or rubbing the person to try to generate warmth because sudden movements that jar the person may lead to a heart attack. For these reasons, it is better to cut off wet clothing when it is difficult to remove it.
  • Person-to-person skin contact is a good way to heat a sufferer from hypothermia. If the person appears to have stopped breathing, check the pulse for a minute (as it will have slowed right down) before starting CPR.

Treatment during hospitalization will involve providing warm oxygen and warm IV fluids.

Prevention & Prophylaxis

To guard against hypothermia, people should avoid going out in the cold air without being adequately dressed. Wearing a hat helps stop body heat from leaving through the head. Mittens are more effective in keeping out the cold than gloves. It is advisable to not be impaired by drugs or alcohol when outdoors during cold weather.