'Cotton kills,' and other need-to-know facts about hypothermia

Jan 11, 2015

Upstate New York’s harsh winters and even harsher winds can be dangerous. One of the health risks, if you are caught out in the elements, or without a source of heat for a period of time, is hypothermia.

This week on “Take Care,” Dr. Chris McStay talks about how hypothermia affects the body and how to prevent it. McStay is chief of clinical operations at the department of emergency medicine at the University of Colorado School of Medicine.

Hypothermia is a core body temperature of less than 95 degrees Fahrenheit, but the severity of hypothermia can vary. There are three different categories of hypothermia: mild, moderate and severe. In cases of mild hypothermia, the temperature of the body falls between 90 to 95 degrees.

Most patients with moderate hypothermia will be awake and alert but still a little confused. In severe hypothermia, there’s a loss of consciousness and often the individual can appear dead.

“Those individuals, between 90 to 95, with mild hypothermia, typically do well with removal from the cold environment,” McStay says. “One of the big risk factors is being in the cold but also being in cold water or being cold and wet.”  

So, it’s important to remove them from those environments and into warmer areas.

However, according to McStay, once the body’s temperature drops below 82 degrees the body begins to lose its ability to shiver. The body cannot effectively warm itself.

“At that point, there are other interventions that need to occur in a hospital setting,” McStay says.

Those methods include adding heat to the body with warm air or intravenous fluids.

Developing hypothermia depends on a variety of factors, including the atmosphere, which affects the way the body cools.

“Staying dry can profoundly impact how you prevent hypothermia,” McStay says. “People can stand very cold environment for many, many hours. Once you start to add in factors like removal of warm clothing, wind and wetness, then it starts to happen quicker.”

When the body begins to lose heat, it has natural reactions, like shivering.

“When the body does drop to a certain temperature, the body has a physiologic mechanism that tells it, basically, to shiver,” McStay says.

Shivering is a contracting of muscle throughout the body and it is almost like walking or exerting yourself, according to McStay. Shivering creates heat and it is how the body warms itself when an individual who is hypothermic isn’t awake or doesn’t have the ability to walk.

It is usually the individuals who create shelter and wait for help that are better off.

"For most individuals who are trapped in a car on a roadside, obviously depending on the outside conditions and a variety of factors, staying in  a car is probably one of the safer places to be,” McStay says.

The first thing to do for individuals who are hypothermic is get them out of that environment and into a warm one. If they are wearing anything that is wet, remove it.

“Cotton that is wet is really bad,” McStay says. “It loses its inflating capacity. We always say… cotton kills.”

McStay says to focus warming individuals at the core of their body; the arms and legs will eventually warm up with the heat that is coming from the core.

“The body typically shunts blood away from the hands and feet and arms and legs and tries to keep warm blood in the core of the body to maintain sort of essential functions of the body,” McStay says.

Another risk factor for hypothermia is age. Older individuals and younger individuals can become hypothermic more quickly.

Family pets are also vulnerable to hypothermia. Your dog or cat is likely more resilient, because of their fur coat and other factors, but they can still get hypothermia when left outside (or in a cold environment) for a long period of time.