When the mercury starts edging over 31 or 30 degrees Celsius in Japan, NHK TV starts issuing periodic warnings to avoid sun exposure. And when the reading reaches 35 or over, a frame appears in the upper left and center of TV screens and stays on for most of the afternoon.
Shukan Jitsuwa (27 July) did not report what was on local TV in Afwaz, Iran a few weeks ago, when the thermometers read a scorching 53.7 degrees Celsius (129.2 degrees Fahrenheit) -- the highest temperature ever recorded in that country. It was also, ominously, the highest June temperature in Asia on record.
In California’s Mojave Desert, the temperature also reached around 50 degrees Celsius, a level considered dangerous to human survival.
“On June 20, a high temperature of 48.3 was recorded in Phoenix, Arizona, which is considered beyond the safe limits for commercial aviation,” a wire service reporter was quoted as saying.
The reason why the readout on medical thermometers does not extend past 42 degrees is because at body temperatures above that, proteins are destroyed.
“The limit of cell tolerance in most mammals is around 50 degrees, but under conditions of extreme dryness, survival at 127 degrees for up to 20 minutes has been recorded,” a science writer tells the magazine. “The reason why survival is possible at high temperatures in a dry environment is that perspiration from the human body quickly evaporates, cooling the body. In the Middle East, the steam from heated moisture does not remain, so evenings are cool, which makes the climate tolerable.” The reason why people can stay alive in Iran even when the temperature goes beyond 50 degrees is because of its low humidity.
“People can get in a bath where the water is 42 degrees, or even in a sauna where the air temperature is close to 80 degrees. The reason the human body doesn’t congeal from the heat is because humans are warm-blooded creatures and the ambient air or water temperature doesn’t immediately affect it,” the aforementioned writer added.
The highest temperature ever to be recorded in Japan was fairly recently, on August 12, 2013, when 41.0 degrees was recorded at Ekawasaki City in Kochi Prefecture. In major cities covered with concrete, the evaporation of moisture tends to be less, making it more difficult to consume the heat, and thereby causing the temperature to rise further. In some U.S. cities, the phenomenon of gasoline boiling in cars’ tanks has led to the caps flying off and fuel spouting from vehicles. At around 50 degrees Celsius, cities’ functions become paralyzed.
An article in a recent issue of science magazine Nature reported that by 2100, three-fourths of humanity risks obliteration in areas of extreme heat. By that time, it may be that the only safe havens left for mankind may be places like Siberia and Alaska, Shukan Jitsuwa’s writer concludes gloomily.© Japan Today