Heat Can Kill
A combination of things - hot temperatures, high humidity, and often pre-existing health conditions can combine to push core body temperatures to the 104 F danger zone.
Heat Can Kill
During the month of June, over 3,000 records for temperature were broken throughout the USA, Queens in New York recording 98 degrees Fahrenheit while Yuma, Arizona hit a scorching 114, meaning that, in the past fortnight, 33% of Americans have been subjected to warnings of both heat advisory and excessive heat kinds.
The trouble is that, while the UK is way cooler and wetter than it should be at this time of year, temperatures in much of the US running a good 10 to 15 degrees above average, meaning that not only are temperatures soaring, but so are heat-related deaths, 23 known about so far, sure to rise as there is no end in sight for the extreme weather conditions.
Forecasters are projecting continued power outages due to the conditions, but why can heat be so deadly, when hot weather alone is not inherently dangerous? The problem, according to University of Oregon environmental physiologist Chris Minson, is a combination of things - hot temperatures, high humidity, and often pre-existing health conditions can combine to push core body temperatures to the 104 F danger zone.
Once this deadly threshold is reached or surpassed, human nervous systems go haywire, hearts come under severe stress, and organ systems start failing, so one must find a way to ensure that we release internal body heat as efficiently as possible, because the build-up of such heat can be fatal.
Even though human bodies have good tolerance high temperatures - experimental subjects have withstood 215 F for up to 30 minutes - there are limits to what it can cope with, as might be expected. As external heat grows the heart starts pumping blood to the skin rapidly, to allow more heat to dissipate through the skin, assisted by sweating, best strategy for cooling down employed by the human body.
Sweat only cools us off when it evaporates, and when high ambient temperatures and high levels of humidity combine, this prevents the evaporating perspiration from lowering core temperatures, so the sweating is no longer effective at cooling us.
Heat stress affects both brain and central nervous system badly, and those with pre-existing health conditions face extra challenges. Warm nights make it hard for tired bodies to recover, and since 1979 over 8,000 people have died from excessive heat in the U.S.A.
The health experts recommendations include being sure to drink plenty of fluids and be watchful for the heat index forecasts - combining predicted temperatures and humidity levels - in your area, to get a better idea of how to respond to the day's conditions. These temperatures are forecast to return to more normal levels within a month, but in the meantime, you need to be extra careful, because there is no doubt heat can kill.