Cooler Summer Raises Risk for August Heatstroke

Photo: Cimexus, Flickr

Phoenix is posting regular 100-degree Fahrenheit days and 90-plus temps are popping up across the country. August is turning out to be one hot month -- especially when you compare it to the cooler temperatures we were seeing in June and July. But be aware that whether outside trimming towering hedges or upping mileage in preparation for a fall marathon, the thermometer's sudden spike is putting all of us at greater risk for heat illness.

Heat illness is a blanket term describing a range of conditions from mild heat exhaustion to deadly heat stroke. With heat illness, your internal temperature is heating up -- you're literally baking from the inside out. Activity is a complicating factor in heat illness as muscles in motion generate big energy, with only 25 percent applied to muscle contractions and the other 75 percent turning into body heat. If the heat doesn't leave your body, core body temps can spike nearly two degrees every five minutes.

Here are a few factors that impact your ability to release the heat:

• Lack of Acclimatization. The New York Times reports lack of acclimatization to the heat is the primary factor predisposing people, in shape or not, to heat illness. Thus, a cooler summer this year with sudden, soaring temperatures in August is a recipe for disaster. If you're feeling strange on your workout -- dizzy, fatigued, just off -- slow down and find shade. It can take five days to three months to fully acclimatize to heat.
• Humidity. Sweat is the body's main tool for removing heat. Humidity slows or even prevents evaporation of sweat. Not good. A humid workout can stop you in your tracks.
• Hydration and Beverage Temperature. Hydration can protect you, but it's not a guarantee. Do stay hydrated, and slip a bunch of ice cubes in your water bottle. A 2008 study showed cyclists who drank beverages cooled to about 39 degrees pedaled way longer in a hot, humid lab than those with a warm, 98-degree beverage.

Be cautious of heat exhaustion or heatstroke. If you or a workout partner show signs of heatstroke, Mayo Clinic advises you to call 911 and take these precautions. The NYT article also reports Immediate immersion in a tub filled with ice or ice-cold water is one of the best treatments to lower core body temperatures fast enough to prevent internal damage or death.