If you like to exercise outdoors, summer gives you more chance to catch the daylight. It’s often easier to get out of bed and still light when you finish work. But what about when it gets really hot?

Everyone can be affected by heat, but babies, young children, older people, those with existing health conditions or on certain medications are more at risk.

Regular exercise throughout the year is crucial for maintaining good health. But in summer you might feel yourself sweating more and wonder if it’s actually risky.

Here are some things to keep in mind when exercising in the heat.

Normally, the body maintains a core temperature around 37°C. Exercising can put more strain on these processes especially when it’s hot and humid. This is because sweating is the body's best way to cool us down and it doesn't work as well in humid conditions.

Heat illness occurs when your body becomes overwhelmed trying to control a rapid rise in body temperature, especially during strenuous activity.

Mild symptoms can include headaches, muscle cramps and feeling faint or sick. Severe cases can lead to seizures, loss of consciousness or even death.

Find out more about heat exhaustion and heat stroke, including how to treat it (Health NZ).

Wearing light, breathable clothing specifically designed for sport will also help with releasing body heat.

How long and hard you train will affect how much heat your body can cope with. Non-continuous exercise such as football can go ahead in hotter conditions than continuous exercise, such as long-distance running or cycling. This is because breaks help the body cool down.

So add additional breaks during organised sport, or take breaks more often during other activities.

You may also need to adjust your routine on hot days. Training during a cooler part of the day (early morning or evening) or exercising indoors can be useful alternatives. You also can’t expect to perform endurance exercise at the same level when it's hot, such as long distance running and cycling.

It’s harder for our bodies to lose heat when we’re dehydrated. Drinking cold or iced water is one of the easiest ways to cool down.

Scientists have found many people unknowingly start their activity dehydrated. So make sure you drink plenty of water not only while you exercise, but beforehand as well.

​Symptoms of moderate dehydration include:

Find out more about dehydration, including how to treat it (Health NZ).