Heat: It's not about being tough

When it comes to weather, we tend not to sweat the small stuff. Heavy wind captures our attention, and so do ice storms and flash floods. But as a general rule, if we can drive through it, then it must not be that bad.

For most people, weather is at its most interesting as a visual element. Watching beads of sweat form on the forehead of a television weatherman simply lacks the impact of that same weatherman leaning into a hurricane-force wind, his cheeks whipping about like the jowls of an old hound.

But while extreme temperature lacks the visual impact of a storm’s aftermath, an Illinois heat wave can be as deadly as a Kansas twister or a Minnesota blizzard. According to the Centers for Disease Control and Prevention, most years about twice as many Americans die from heat-related illnesses than from tornadoes, earthquakes and floods combined. Extreme heat is not, as some might believe, too much of a good thing. It’s a dangerous air mass, as different from ordinary summer heat as a thunderstorm is from a gentle spring shower.

Dangerous heat is measured by the heat index, meteorologists’ way of answering the question, is it the heat or the humidity? The answer is, it’s both. The heat index is summer’s response to the wind chill factor, measuring temperature and relative humidity to determine how hot the body feels.

The body cools itself through evaporation, changing liquid sweat to vapor, and thus removing heat from your skin. But high relative humidity obstructs evaporation, hampering the body’s ability to cool itself. That raises the body temperature to a point where heat-related illnesses such as heat stroke may develop.

We offer this science lesson not to belabor the point, but as a reminder that heat-related illnesses are a matter of biology, not a character flaw. It’s not about being tough enough to stand the heat, but being smart enough to stay out of trouble. Heat is the most easily predicted weather extreme, yet still claims the most victims. So don’t just suck it up – be smart about it. Drink plenty of water, stay inside or at least in the shade as much as possible, and save your exercising for mornings or evenings, avoiding mid-day, when the heat index is often at its peak.

Also, be sure to check on loved ones, particularly those living alone, and never, ever leave children or pets in a vehicle, where the heat index can rapidly escalate. Common sense is all is takes for most of us to protect ourselves from potentially deadly heat. But as temperatures rise, too often common sense is all too uncommon.