The Body's Response to Cold Temperatures

The body is equipped with ways of generating additional heat when the surroundings are cooler than the body's temperature. For example, muscles contract and produce additional heat by shivering. The body is also equipped with ways of keeping what heat it has. For example, small blood vessels just below the surface of the skin narrow (constrict) so that more blood goes to the heart and brain. However, aging itself takes its toll on the body's ability to adapt to the cold. With aging, the body becomes less efficient at shivering or at diverting blood away from the surface of the body. Also, the layer of fat just under the skin thins, so there is less insulation to prevent heat loss.

The body's ability to produce heat is decreased by diseases that commonly affect older people, such as hypothyroidism. The body's ability to retain heat is decreased by diseases such as diabetes. A person who is less able to move around because of an injury or a disease such as a stroke or arthritis is also at a greater risk of dangerous cooling, because the decreased movement generates less heat-producing muscle activity. Alcohol and certain drugs, such as antidepressants, increase the risk as well.

Back to Hypothermia.