With age, the body perspires less. Both of these age-related skin changes make it more difficult for an older person to adjust to heat. Another age-related change that affects overheating is thirst. Older people are less likely to feel thirsty, and therefore may not drink enough water. The more medications one takes, the more likely an interference with the body's fluid balance.
Some drugs contribute to dehydration or fluid retention.
Drugs that are known to interfere with fluid levels include Lasix and Hydrocholorathiazide. Summer Heat Concerns Dr. Wolter explains the difference between heat exhaustion and heat stroke. Heat exhaustion typically occurs after exertion, such as mowing the lawn, jogging, or moving furniture. The symptoms of heat exhaustion include feeling dizzy, weak, hot, and nauseated. You might have a headache, experience shortness of breath, and a loss of appetite.