‘When it's hot, I drink at least two more cups of water than usual,' says marathon runner Robert McLane. If you're going out early, ‘hydrate throughout the day before,' says Aaron Runyon. The rule of thumb is to aim for 500ml to one litre of fluid per hour of exercise, or 100ml to 200ml every 15 to 20 minutes. Make sure you hydrate with fluids containing electrolytes since you will be sweating a lot of salt out. Look for a drink that contains 25 to 50 grams of carbs, 230 to 345 milligrams of sodium, and 40 to 100 milligrams of potassium.

Run Very Early or Very Late

‘We meet up anytime between 4 and 5am so we can be done around the time the sun rises,' says Elizabeth Hensley, where the normal high in December is 36°C. If you can't go early, go as late in the day as possible. Although the sun is highest in the sky at noon, the earth's surface heat peaks between 3 and 5pm. ‘I run at midnight,' says Nick Davis, ‘I wear just shorts and shoes.'

Plan Ahead

Run in a park with water fountains or on a route with petrol stations. ‘I map my run to make sure I can refill my bottles,' says Dominique Perrier. Or stash a cache. ‘My weekday runs are usually a series of loops in the neighborhood, so I can double past my house, where I leave water or a sports drink by my post box,' says Warren Biddle. ‘I sometimes ride my bike or drive the route and leave some water along the way,' says Sloan McLaughlin, who lives in Egypt. Jesse Mack keeps a cooler at the end of his street with water, energy drink and a hat. ‘I grab a drink and switch hats, so I get a cooldown every loop.'

Check the Index

It's not the heat, it's the humidity. ‘Last summer, it was 31° at 8pm, but it's high humidity that will get you,' says Runyon. Moist air slows down your body's ability to cool itself through sweat. The discomfort index combines temperature with relative humidity to give you the apparent temperature - how hot it actually feels. ‘I check the weather forecast the day before my long run to decide how early to go out,' says Johan Havenga. ‘Here the temperature doesn't drop much at night, and humidity is higher in the early hours.'

Wear the Right Stuff

‘Last summer, I ran with a lightweight long-sleeved top that wicks,' says Gaeten Dominic. ‘My skin temperature stayed cooler for a more pleasant run.' Light-colored clothing reflects heat, and a loose fit lets air circulate. Hats are useful for more than blocking rays. ‘I pack ice under my hat, which lasts about 40 minutes,' says Roger Trudeau, who lives in Tunisia. ‘The cooling effect of the water running down over me makes all the difference.'

Get Used to It

The good news is your body begins to adapt to elevated heat in only three or four days, though it might take up to two weeks to acclimatize. ‘Running in Guadalajara, Mexico, it's hot most of the time, so my 'secret' against heat is facing it on a daily basis,' says Alberto Aguirre. ‘Long distance runs of 30km at noon are tough, but if you do it twice, you will be ready to finish even if the heat is on.'

Be Sensible

‘If you ever feel nauseous or heavy-headed, stop immediately, get in the shade and drink something cold,' says Rik van der Vaart, who speaks from experience, having suffered heat stroke when he first moved to tropical Aruba 10 years ago. Tara Sweeney adds to the list of warning signs: ‘If you are feeling dizzier than normal, are feeling sick, or are not sweating, then you need to stop and get inside somewhere cool.' Michael Bower says, ‘Above all, listen to your body and what it says. It knows more than you do.'

Seek Shade

Elizabeth Hensley's running group avoids the heat as much as possible. ‘Any time you can spend in the shade will help - stretching, warmups, even water breaks,' says Hensley. Plot routes through residential areas. ‘There's more shade in the neighborhoods, plus there's usually the opportunity to run through a few sprinklers,' she says. Or run by larger bodies of water. ‘I run near a river or reservoir since it is naturally cooler,' says Maritsa. It can get very, very hot in the summer.

Race Easy

Save the 42.2km races for autumn, since the optimum marathon temperature is 12°C. Every seven degrees above that, your overall time slows by a minute or more. ‘My 10km race pace at 27 degrees is at least 10 percent slower than at 16 degrees,' says Michelle Ginsburg. Jeannie Runyon says she and her husband stick to local 5kms. ‘That way we can enjoy the race-day experience without spending hours in the heat.' Even with the shorter distances, forget about PBs. You can't expect to race all out.

Enjoy

‘I put on a pair of lightweight racing shoes, sunglasses and racing shorts, and run shorter routes more often,' says John Fletcher. ‘I feel like I'm flying.' Cool off by standing under a garden hose as does Victoria Stopp taking a cold shower, or getting in a pool. ‘I jump into the pool and cool my body off before I start,' says Donna Parsons. Amanda James freezes paper cups of energy drink with sucker sticks for a post-run recovery snack. Appreciate the light mornings and the absence of pouring rain. Remember, it'll be cold again soon enough.

Sandra Prior runs her own bodybuilding website at http://bodybuild.rr.nu.