How hot is too hot for exercise? Plus how to do it safely in summer

Exercising in the heat puts you at risk of dehydration, heat exhaustion and other serious illnesses. Here are guidelines on doing it safely

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Take care and follow simple precautions when exercising in the summer to avoid dangerous heat-related conditions. Photo: Shutterstock

Published: 5:32pm, 25 Jun 2025Updated: 5:45pm, 25 Jun 2025

Extreme heat makes it especially hard for your body to cool down, so you need to be extra careful if you exercise or play sports when it is baking outside.

Your brain tries to keep your body around 98.6 degrees Fahrenheit (37 degrees Celsius) and it does so in part by triggering sweat. When sweat evaporates, it carries away heat from your body’s surface.

When sweat cannot do its job – because your body is generating a lot of heat or it is too hot and humid to cool down – you are at risk of dehydration or a heat-related condition such as heat exhaustion or heatstroke.

Bharat Venkat, an associate professor at the University of California, Los Angeles (UCLA), and the director of the UCLA Heat Lab, says heat can affect the entire body.

“We’ll often talk about heat cramps. We’ll talk about heat exhaustion. We will talk about heatstroke. But it’s actually much wider than that. Heat can really impact every system in our body, our hearts, our lungs,” he said.

Heat can affect the whole body, says Bharat Venkat, an associate professor at the University of California, Los Angeles (UCLA) and the director of the UCLA Heat Lab. Photo: UCLA

How hot is too hot for exercise? Plus how to do it safely in summer

Exercising in the heat puts you at risk of dehydration, heat exhaustion and other serious illnesses. Here are guidelines on doing it safely

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