When the humidity is low, the apparent temperature is lower than the actual
temperature. When our bodies aren’t cooled effectively by sweat evaporation,
we really do get hotter. But, although our body cooling systems work best when
the humidity is low, it is not necessarily true that we will be comfortable in dry
weather. If the air temperature is much higher than body temperature and the
humidity is only 10%, you’ll still feel hot, as any permanent resident of south-
ern Arizona will tell you. “Dry heat” can, in fact, be more dangerous than
“muggy heat,” because people are less aware of how high the temperature
really is. This can lead to a sense of overconfidence, with potentially serious
consequences.
COPING WITH HEAT
Unpleasant effects of hot weather include dehydration, cramps, exhaustion,
drowsiness, irritability, and depression. In hot weather, it is important to stay
hydrated. This is especially true for children, who often run around with com-
plete disregard for the weather. An easy way to see if you are dehydrated is to
weigh yourself at frequent intervals. A liter of water weighs a kilogram; a pint
weighs about a pound. Thus, for example, if you suddenly lose 4 pounds, you
have lost 2 quarts (about 2 liters) of water. That might not be serious if you are
a linebacker for a professional football team, but for a 5-year-old child it repre-
sents a significant water loss.
The best way to hydrate is to drink a little water at frequent intervals. Other
liquids can be substituted for water, but they might not relieve thirst as effec-
tively as water, and some beverages have side effects. Beverages containing caf-
feine or theobromine, such as iced coffee or tea, should not be consumed in large
quantities because they have a diuretic effect that can worsen dehydration and
cause mineral loss, besides producing agitation and heart palpitations in some
people. Beer is alright in moderation, but large amounts of alcohol hinder the
body’s ability to regulate its temperature. “Hard” drinks must be avoided because
they can quickly and dramatically worsen dehydration. Pure orange, grapefruit,
or tomato juice, as well as other fruit and vegetable juices, are excellent, as long
as they aren’t loaded with sugar.
Some athletes and coaches believe that salt tablets can help prevent exhaus-
tion and cramps in hot weather. Others advise against taking them, and insist
that it is potassium loss, rather than sodium loss, that causes the most trouble,
and that you’re better off eating a banana than taking a salt tablet. Consult your
doctor concerning the advisability of taking any type of nutritional or chemical
supplement to help you deal with the heat.
CHAPTER 8 Abnormal Weather
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