Although June 22 is the official start of summer, we’ve had summer conditions here since mid-May, and I’m already sick and tired of it. It’s a long, hot summer here in Central Florida, extending from mid-May to mid-October.

We seldom get a break from the heat and humidity. No need to check the weather forecast. We can recite it from painful memory. It doesn’t change. High today, 95; low tonight 75. There’ll be a regularly scheduled thunderstorm at 4:00 PM every day, which sometimes, just for variety, bring damaging hail, strong winds, frequent lightning, and, once in a while, tornadoes. What they don’t do is cool us off. They merely increase the humidity, and hence, the discomfort level.

It is the usual thing to see the temperature-humidity index (THI) exceed 100. Bad things happen to humans at those levels—heat strokes, breathing difficulties, and heart attacks, just to name a few. When the ambient temperature is above body temperature (98.6F/37C), and the humidity is high, it is difficult for the body to employ the standard sweating mechanism to cool itself off. When you stop sweating, that’s the first sign of trouble. The blood flows to capillaries near the surface of the skin in a feeble attempt to radiate heat, but that mechanism is impaired, so major organs are deprived of blood, body temperature increases, and bad stuff starts to happen. [Read more…]