The elderly are at higher risk than the general population for temperature-related health issues. The body's reduced ability to regulate temperature, medical problems, medications and the environment are all factors affecting the ability of elderly individuals to maintain a healthy body temperature. Dangerous body temperatures are below 95 degrees Fahrenheit or above 104 degrees Fahrenheit for the general population. Elderly individuals have a narrower range of safe temperatures, varying by approximately 2 degrees on either end of the scale.
Healthy young adults adapt to temperature changes through various processes aimed at core body temperature maintenance. Sweating cools the body and shivering warms the body. Although there is variation among individuals, the elderly lose these thermoregulation functions, with reduced ability to sweat and shiver. Blood circulation problems increases thermodysregulation responses. Decreased thirst awareness affects body temperature in the elderly, as dehydration further reduces the body's ability to maintain a steady temperature.
Hypothermia results when an individual's core body temperature drops below 95 degrees Fahrenheit. While vasoconstriction and shivering in healthy young adults act to increase the body temperature and prevent damage, the elderly do not respond with these autonomic reactions until their temperature is significantly lower. Furthermore, the geriatric population has a prolonged reaction to hypothermia, taking longer to respond to interventions to help them warm up and return to a healthy temperature.
Hyperthermia is the result of the body overheating. The elderly are at higher risk for hyperthermia because of the normal aging process of decreased autonomic responses for cooling, chronic medical conditions and certain medications. Symptoms of hyperthermia range from uncomfortable to life-threatening. Cramps caused by excessive heat are accompanied by moist, cool skin. Swelling of the ankles and feet, edema or sudden dizziness known as heat syncope can result from overheating. Heat exhaustion causes dizziness, thirst, sweating and nausea, but the body temperature remains normal. Heat stroke results when the body temperature exceeds 104 degrees Fahrenheit. Confusion and fainting are signs of this medical emergency.
Measures to prevent dangerous body temperatures when the weather is hot include drinking water, avoiding alcohol and caffeine, taking cool baths or showers, staying indoors during the heat of the day, using cooling fans or air conditioners and avoiding excessive exercise. Special care should be taken to keep the elderly warm in cold environments, including operating rooms. The slower temperature regulation reaction times and the prolonged recovery times from hypothermia make it necessary to take measures to reduce heat loss in the elderly by using warm blankets, warm baths or other means of conserving heat.
- Medline Plus: Aging Changes in Vital Signs
- Harvard Health Publications: Normal Body Temperature: Rethinking the Normal Human Body Temperature
- Centers for Disease Control and Prevention: Heat Stress in the Elderly
- Senior Journal: Hyperthermia: When It's Too Hot for Elderly People's Health
- National Institute on Aging: NIH Tips for Older Adults to Combat Heat-related Illnesses
- Senior Living Choices: Heat and the Elderly