How Dangerous is it to Exercise Outdoors in a Heat Wave?

O’Hare airport recorded a 94-degree high Saturday –the 9th 90-degree day so far this month and 14th of the season

Yesterday I delineated the danger signs of exercising in hot weather, but didn’t explain exactly how heat impacted the body itself.

Also I mentioned in an earlier post that my doctor told me not to go biking when there are 90 plus degree heat advisories. My daily biking has brought my resting heart rate down below 50 and I have less than 17 percent body fat on me. I am in great shape and prior to my doctor warning me about it, I had ridden regularly in heat waves. She said that despite my conditioning it was not safe for me. She said that she also told her 40 year old patients not to go out either.

I have to confess that I was skeptical about this. I do believe in following ‘doctor’s orders’ and I have not gone out in the hottest part of the day on my bike, but I have been tempted. I feel great and know how well my body responds, so it seems safe. BUT, I don’t plan on doing it.

I did a little research on it, wondering exactly why it was dangerous to experience exercise stress in heat.

Here is how the Mayo Clinic explained it:

How heat affects your body

“Exercising in hot weather puts extra stress on your body. If you don’t take care when exercising in the heat, you risk serious illness. Both the exercise itself and the air temperature increase your core body temperature. To help cool itself, your body sends more blood to circulate through your skin. This leaves less blood for your muscles, which in turn increases your heart rate. If the humidity also is high, your body faces added stress because sweat doesn’t readily evaporate from your skin. That pushes your body temperature even higher.
Heat-related illness
“Under normal conditions, your skin, blood vessels and perspiration level adjust to the heat. But these natural cooling systems may fail if you’re exposed to high temperatures and humidity for too long, you sweat heavily and you don’t drink enough fluids. The result may be a heat-related illness. Heat-related illnesses occur along a spectrum, starting out mild but worsening if left untreated.

Heat illnesses include:
Heat cramps. Heat cramps are 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. With heat exhaustion, your body temperature rises as high as 104 F (40 C) and you may experience nausea, vomiting, headache, fainting, weakness and cold, clammy skin. If left untreated, this can lead to heatstroke.

Heatstroke. Heatstroke is a life-threatening emergency condition that occurs when your body temperature is greater than 104 F (40 C). Your skin may be hot, but your body may stop sweating to help cool itself. You may develop confusion and irritability. You need immediate medical attention to prevent brain damage, organ failure or even death.”

I consider this to be an excellent articulate explanation of the dangers of subjecting your body to exercise stress during periods of extreme heat and it convinces me that I need to avoid it.

I hope it clarifies the situation for you, too.

For some further suggestions on dealing with extreme heat, check out How to Beat the Heat and Hydration – Cool, Clear Water. What are danger signs during hot weather exercise?,What about bike riding during a heat advisory? What to do about exercise in very hot weather? How to beat the heat?

A word to the wise…

You can check my Page – How to deal with extreme heat for more.



Filed under aging, Exercise, hot weather, life challenges, Weight

5 responses to “How Dangerous is it to Exercise Outdoors in a Heat Wave?

  1. Pingback: What to do About Exercise During a Heat Advisory | Two Regular Guys Talking about Food, Exercise and Men's Health

  2. Pingback: What are Danger Signs During Hot Weather Exercise? | Two Regular Guys Talking about Food, Exercise and Men's Health

  3. Pingback: How to Beat the Heat | Two Regular Guys Talking about Food, Exercise and Men's Health

  4. Pingback: What To Do If You Get Overheated | Two Regular Guys Talking about Food, Exercise and Men's Health

  5. Reblogged this on One Regular Guy Writing about Food, Exercise and Living Longer and commented:

    As we sit here on the brink of summer with record heat on the West Coast as well as the Southeastern U.S., I thought it useful to reblog this item I wrote during a heat wave a while back.

    Parents, please keep in mind that you must not leave little children in hot cars. The Weather Channel reported that there have already been NINE deaths to young children already this year.



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