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How 100 Degrees Does a Number on You

By Susan Brink for National Geographic
7/18/2013 11:58:08 AM

The following is an excerpt from National Geographic.

The heat wave of 2013 continues. This week it's in the East Coast, where temperatures are expected to soar into the mid-to-high 90s (degrees Farenheit). And there's no relief at night: Lows are expected to hover in the low 80s. The West will see temperatures in the 90s.

That's relatively bearable compared with the triple-digit sizzlers of late June, when temperatures hit 119 in Phoenix. And this week, the 108-degree temperature in Las Vegas will still be high enough to cause second-degree burns for anyone attempting a barefoot walk across a parking lot.

A boy jumps into a water canal to cool himself on a hot day in Pakistan, where temperatures reached 109 degrees Fahrenheit (43 degrees Celsius) in June. Photograph by Mohsin Raza, Reuters

These brutally high temperatures have spread beyond the nation's well-known summer ovens, with the heat wave-technically defined as three days in a row with temperatures topping 90 degrees-hitting traditionally cooler parts of the country, like the Northwest, and baking the northeast well into Canada.

From Arizona to Montana, from the Great Lakes to Maine, people are hearing heat advisories and warnings.

They do well to heed those warnings, says Claude Piantadosi, director of the Duke Center for Hyperbaric Medicine and Environmental Physiology in Durham, North Carolina. Human beings aren't built to spend long periods of time in temperatures that top the body's own approximate 98.6 degrees.

To find out more about how the human body cools itself in times of high heat and the worst case scenarios of the heat waves, click here.

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