Ask the Expert: Handling the Heat Better

June 17, 2024 – Defence Stories

Q: Several of my friends have had heat-related injuries while exercising, and one even needed several weeks to recover. Are there strategies to make exercising in hot weather safer and more enjoyable?
- Perspiring Perry

A: Dear Perspiring Perry: Hotter summers can make outdoor physical activity more challenging. During exercise, your working muscles generate a lot of heat. Your body uses several mechanisms to dispose of the heat you generate but these mechanisms can be overwhelmed in hot weather, especially if you are not acclimatized. The following strategies can help you cope with exercising in the heat:

1. Be sure to hydrate – Drink fluids before, during, and after your training. What you drink is important. Avoid energy drinks and alcohol because they are dehydrators. When you exercise for less than an hour, hydrate with water. If you work out intensely for longer than this, hydrate with an electrolyte drink.
2. Be wise - acclimatize – It takes several weeks (not several hours) of exercising in the heat for the body to learn to handle heat stress more efficiently. Consult the weather report to see if the temperature, humidity, or UV index are significantly higher than those you are used to.
3. Pull back on the throttle – Reduce the intensity of your training in hot weather, especially if you are not acclimatized.
4. Adjust if you feel unwell while exercising – Not everyone reacts to heat the same. Nausea/vomiting, dizziness, headache, unusual fatigue, cramps, and rapid pulse are all signs of heat stress. If you develop these symptoms, don’t hesitate to reduce your intensity or stop.
5. Stay away from peak heat during the day – You will be more comfortable if you train in the early morning or after the sun goes down.
6. Seek the shade – Forest trails provide a significantly cooler environment to train in.
7. Clothing is important – Don’t overdress and try wearing light-coloured clothing made of breathable materials.
8. Back off if you are ill – When you are ill and your body is already under stress, having to also deal with the heat could be overwhelming.
9. Think of other locations or alternative activities – Consider doing your workout in an air-conditioned environment, going for a swim, or taking a day of rest.

Bottom line: Exercising in the heat puts stress on your body and can be dangerous, especially if you are not acclimatized. Heat-related injuries can be prevented – follow the above strategies to make your summer exercise safer and fun. Exercise is medicine- even in the heat!

You can find more information at: CCOHS: Hot Environments – Health Effects and First Aid and 4440-22 Heat Stress Prevention Advisory | MPC

Dr. Darrell Menard OMM MD, Dip Sport Med
Dr. Menard is the Surgeon General’s specialist advisor in sports medicine.

Strengthening the Forces is the CAF/DND’s health promotion program providing expert information, guidance, training, tools, and leadership support to improve CAF members’ health and well-being.