How extreme heat can kill you
Posted August 6
With a heat dome hovering over much of the country, paramedics are treating heat stroke and other illnesses brought on by extreme temperatures. The victims include a 55-year-old South Carolina man who collapsed and died while out on a walk, and a 20-year-old California football player who was in a coma for two days after suffering heat stroke during practice.
A normal internal temperature for a human being is a sweltering 98.6 degrees, so why are humans so ill-equipped to deal with heat outside our bodies?
Like a car engine, our bodies create heat with all the work they do to digest food, distribute nutrients, build muscle, pump blood and perform other functions. Scientific American has reported that the body's essential functions work best when the air temperature is around 70 degrees Fahrenheit.
The higher it goes above that, the harder our bodies have to work maintain equilibrium. High temperatures, particularly when combined with humidity, interfere with the body's normal process of throwing off all that heat, such as circulating blood near the surface of the skin and evaporating sweat.
When we're unable to sweat, our internal temperatures rise and our organs begin to overheat. Dehydration impedes blood flow. Our temperature may reach or exceed 105 degrees within 10 or 15 minutes of sustained heat.
"Heat stroke is the worst kind of heat illness, and it can sneak up on you," Corin Hoggard wrote for ABC 30 Action News in Fresno, California, where the Fresno State football player is recovering after a heat-induced coma.
Signs of imminent heat stroke may include headache, dizziness, muscle weakness or cramps, and nausea or vomiting. Although overheated, the person may not be sweating. The heartbeat is rapid and breathing is ragged, and a person becomes disoriented and may have a seizure before losing consciousness.
Thirty to 40 percent of people who suffer heat stroke die from it, even when treated, TIME magazine reported last year.
Adults 65 and older and children younger than 5 are most at risk for heat stroke, according to the Centers for Disease Control and Prevention.
But obesity also elevates risk, as does heart disease, sunburn and poor circulation. People who regularly drink alcohol or take prescription drugs are also at higher risk, as is anyone who is already dehydrated.
But even young, healthy people in optimal shape can succumb to heat stroke or heat exhaustion if they push themselves in extreme heat.
In 2009, the National Athletic Trainers' Association released guidelines for athletes practicing in heat. High-school football players, in particular, are vulnerable to heat-related illnesses because of late-summer workouts. Since 1980, 44 high school football players died from heat stroke, according to Medline Plus.
And a study published in the Journal of American Cardiology in 2014 concluded that heat stroke is more deadly than cardiac events among distance runners.
Heat stroke is different from heat exhaustion, both in symptoms and treatment.
Heat exhaustion is marked by weakness, dizziness, muscle cramps and heavy sweating. It can be treated by drinking clear juice or a sports beverage, moving to a cooler location, and taking a shower or sponge bath, according to the CDC.
In contrast, heat stroke requires emergency medical treatment. While waiting for help to arrive, cool the person by moving him to a shady location, fanning him and bathing his body with cool water.
To help prevent heat stroke, don't exercise during the hottest times of the day, drink plenty of fluids to ward off dehydration, and spend time getting acclimated to heat over one or two weeks. The Korey Stringer Institute at the University of Connecticut also recommends that athletes (and this goes for you weekend warriors, too) take frequent breaks, keep iced towels or ice tubs on hand, and increase sodium intake during hot spells.
And appreciate summer while you can. There's only 94 shopping days until Halloween.