When pushing yourself in the heat, be on guard for symptoms of heat injuries:
Heat cramps. Painful muscle contractions, mainly affecting the calves, quadriceps and abdominals. Affected muscles may feel firm to the touch. Your body temperature may be normal.
Heat exhaustion. Your body temperature rises as high as 104 degrees and you may experience nausea, vomiting, headache, fainting, weakness and cold, clammy skin. If left untreated, this can lead to heatstroke.
Heatstroke. This life-threatening emergency condition occurs when your body temperature tops 104 degrees. Your skin may be hot, but you may stop sweating, which helps your body cool itself. You may become confused and irritable. You need immediate medical attention to prevent brain damage, organ failure or even death.
Source: Mayo Clinic.
Keep summer exercise from turning into a death march by preparing as you would for a deployment in the heat: by acclimating.
With a smart acclimation plan, you'll be better prepared to perform well and lower your risk for heat injury.
As you train in hotter environments, your body adapts to heat stress by increasing blood volume — which improves your body's ability to sweat.
"As you acclimatize, you become a little bit more efficient," says Army Col. (Dr.) Francis O'Connor, medical director of the Consortium for Health and Military Performance in Bethesda, Md.
You'll start sweating sooner, you'll sweat more, and that sweat will be diluted so electrolyte loss slows. All of that helps you stay cooler and on your game. Fully acclimating takes 10 to 14 days. Fitter athletes may adapt sooner, but you have to put in the training time.
"Acclimatization is most quickly accomplished through daily exercise sessions in the heat that last a minimum of one or, preferably, two hours per day," according to the military's Human Performance Resource Center. If living, working and working out in the specific climate are impossible, experts suggest training in the heat of the day or in a sauna — anything that will mimic the conditions.
Too late to acclimate?
Any athlete, acclimated or not, can benefit from pre- and mid-workout cooling strategies. A cold shower before a session lowers your core temperature. Using a water mister while you work out will also help keep you cool. These methods of "heat dumping" can help prevent a heat injury but shouldn't be used as treatment.
If you don't cool down enough between workouts, then you could run into cumulative heat issues.
"The military has been really prolific in showing that you can accumulate heat over days, and that many of our heatstrokes occur as a result of two to three days of extremes of temperature," O'Connor said.
You'll know you haven't dumped enough heat if you see signs such as irritability, personality changes or a headache, O'Connor said.
But for any hot workout, the best advice hasn't changed: Be smart, know your body and know when to take it easy.
"You definitely have to listen to your internal governor and modify intensity," O'Conner said. "No matter what strategy you try to use, you have to individualize it. You have to practice it. Just because it works for somebody ... doesn't mean it's going to work for you."