Surviving extreme heat poses special problems for older people, says the Harvard Health Letter
Killer heat waves such as the one blamed for 14,800 deaths in France in 2003 may become more common. Global warming is one part of the problem. Another part is the growing number of people who are more vulnerable to the heat because they're older and heavier, the July issue of the Harvard Health Letter explains.
Thirst declines with age, and older sweat glands don't produce as much sweat as they used to. The sweat that is produced tends to contain more salt, and lack of salt in the body can lead to sudden drops in blood pressure.
Older people are also more likely than younger folks to be taking medications that cause fluid loss (and therefore dehydration), including some laxatives, furosemide (Lasix) to counteract water retention, and other diuretics for blood pressure control.