COLUMBIA — On Sunday afternoon, former gymnast Adrianne Perry and her boyfriend went for a run at Stephens Lake Park. She's training for a marathon in September.
"We started running at 3:30 (p.m.) and we were running for 2 ½ hours, and we almost died,” she said.
Summer temperatures are already in the 90s and Boone County is under a heat advisory until 7 p.m. Saturday, according to the National Weather Service. Highs will be in the upper 90s and the heat index could be between 100 and 105 degrees in the afternoons and early evenings.
As Perry learned the hard way last Sunday, when the temperature is peaking, the risks are highest. Replacing fluids is key.
Richard White, an assistant professor of Clinical Orthopedic Surgery for MU, warned that anyone performing strenuous physical activity should be aware of the signs of heat stroke. If you get to the point where you are overly thirsty or you stop sweating, it’s too late, he said.
“If it’s gone to a heat stroke, you’ve already gone beyond your body’s ability to regulate. You should seek medical attention immediately,” he said.
Heat stroke and heat exhaustion are dangerous possibilities when the heat index begins to rise, and doctors recommend that fitness enthusiasts take the necessary precautions.
“I guess the main thing specifically for the heat would be the hydration,” White said.
White explained that one pound of weight loss is equal to one pint of fluid loss. People should keep that in mind to gauge how much fluid they need to replace.
A one-percent loss of body weight in fluid impairs your ability to maintain your body temperature. A three-percent loss impairs oxygen utilization. At seven percent, a collapse is likely.
While heat stroke and heat exhaustion are risks to anyone out in the heat, they’re not unavoidable.
Exercisers should wear loose, airy clothes, take breaks when needed and stay hydrated to replace lost electrolytes.
Even with the severe heat in the last few days, there have only been four patients treated for heat-related illnesses so far this year in Boone County, said Genalee Alexander, a spokeswoman for the Columbia/Boone County Public Health and Human Services Department, on Wednesday.
But the actual number of people collapsed on their couches in front of their fans is unknown.
Missourian reporter Emily David contributed to this report.