Tennis in the Heat: A Summer Survival Guide

Heat is the one opponent on the tennis tour that has beaten absolutely everyone. It made Jannik Sinner — the fittest, most relentless young champion in the men's game — stop in the middle of a match with his legs locking into cramps. It left Novak Djokovic, a man who has won everything there is to win, bent over and vomiting on court before he could finish off a victory, openly lamenting the conditions afterwards. If the heat can do that to the two best-conditioned athletes on earth, imagine what a baking July afternoon can do to the rest of us, out on a public court with a friend and a single warm bottle of water.

Tennis and brutal heat have always gone together, and the sport is finally taking it seriously. So whether you are watching the pros wilt this summer or planning to get out and play yourself, this is what the heat is actually doing to a body on a tennis court — and the genuinely effective ways, from the professional tour down to the park, to beat it.

Tennis has nowhere to hide from the sun

Start with why tennis, of all sports, is so uniquely punishing in the heat. Most sports have a clock. Football, basketball, rugby — they end at a fixed time, win or lose, so the heat can only get at you for ninety minutes or so. Tennis has no such mercy. A match ends when someone has won enough games, and on a bad day that can mean three, four, even five hours out there with no guaranteed finish line in sight. You cannot simply run out the clock and escape into the shade.

Then there is the exposure. A tennis player stands in the middle of an open court, usually with no roof, no shade and nowhere to hide, often in the hottest part of the day because that is when matches are scheduled. Hard courts make it worse still, soaking up the sun and radiating heat back up from the surface, so the temperature at ball level can be markedly higher than the official reading taken in the shade. Add the explosive stop-start running, the constant changes of direction, the sheer physical effort of hitting a ball hard for hours, and you have a near-perfect recipe for cooking an athlete slowly from the inside out.

The rule that finally said "enough"

For years the players simply suffered, and the sport mostly shrugged. That is now, at last, changing. From 2026, the men's ATP Tour has introduced a formal extreme-heat rule — catching up, some thirty years late, with the women's WTA Tour, which has protected its players from dangerous heat since the 1990s.

The clever part is how it measures danger. Rather than relying on the air temperature alone, which tells you very little about how a body actually copes, the rule uses something called the Wet Bulb Globe Temperature, or WBGT — a combined reading that folds in heat, humidity, sun and other factors to estimate the real physiological stress on a person. Under the new policy, once the WBGT hits 30.1°C during either of the first two sets of a best-of-three match, a player can request a ten-minute break to get off court, change clothes, shower, cool down and rehydrate. And if the WBGT climbs past 32.2°C — roughly 90°F — play can be halted altogether. The four Grand Slams, including Wimbledon, along with the Olympic tournament, run their own WBGT-based heat policies on similar principles. The era of just gritting your teeth and dropping is, mercifully, ending.

What the heat is actually doing to your body

Here is the part that should change how you play, because the danger arrives far earlier and more quietly than most people realise. By the time you actually feel thirsty on a hot court, your body is already around two per cent dehydrated. Thirst is not an early warning; it is a notification that you are already behind, and on a tennis court, behind is a difficult place to come back from.

And the consequences stack up fast. For every single per cent of body weight you lose to sweat during play, your core temperature can climb by about half a degree Fahrenheit, and your heart is forced to work an extra three to seven beats per minute just to do the same job at the same pace. In other words, the more you sweat without replacing it, the hotter you get and the harder your heart labours — a spiral that ends, if you ignore it for long enough, in the cramping, dizziness and collapse you see even at the very top of the sport. Cramp in particular is closely linked to losing too much salt: heavy sweaters who shed a lot of sodium are far more prone to those sudden, agonising muscle seizures, which is why plain water alone is often not enough to keep you upright.

Hydration: start early, drink smart

Which brings us to the single most important thing you can do, and the thing nearly every amateur gets wrong: hydration is something you win or lose before you ever step on court, not during. The professionals arrive at a hot match already topped up, having drunk steadily for hours beforehand, because they know that once you are behind in the heat you almost never catch up mid-match. Sip early, sip often, and do not wait for your body to ask.

Plain water is fine for a gentle hit, but for anything long or genuinely hot it is not enough on its own, precisely because of that salt-loss problem. This is why so many players reach for electrolyte tablets or hydration powders rather than water alone — replacing the sodium you are sweating out is what actually keeps the cramps at bay, and the sports-science guidance is to add a meaningful amount of sodium to your drinks during hot, extended play rather than relying on water to do a job it cannot. Get the hydration right and you have solved more than half of the heat problem before you have hit a single ball.

Block the sun before it blocks you

Hydration keeps you running; sun protection keeps you from paying for the day for the rest of your life. Hours under direct summer sun, week after week, is one of the most reliable ways to damage your skin and your eyes, and tennis players rack up more of it than almost any other recreational athletes. A sweat-resistant sport sunscreen that will not run into your eyes the moment you start to perspire is not optional equipment in summer; it is as essential as your racket.

Your eyes need defending too. Squinting through glare off a bright hard court is exhausting, wrecks your ability to track a fast-moving ball, and does your eyes no favours over the years. A proper pair of tennis-specific sunglasses — built to stay put during hard movement and to cut glare without distorting the ball — genuinely improves both your comfort and your tennis on a blazing day, and a hat or visor to keep the sun off your face completes the set. None of this is vanity. It is the difference between enjoying summer tennis and merely surviving it.

Cool the body down, the way the pros do

Watch a changeover at any hot tournament and you will see a whole choreography of cooling that you can copy almost exactly. The players are not just resting; they are actively dumping heat. Ice towels draped around the neck and shoulders, cold drinks, handheld fans, a wet cap pulled back on — every ninety seconds of a changeover is spent fighting the body temperature back down before the next game.

You can do the same on a public court for almost nothing. A simple cooling towel — the kind you soak, wring out and snap to activate — held against the back of the neck during changeovers makes a startling difference, because the neck carries large blood vessels close to the surface and cooling there cools the blood heading to your brain. Find the shade at the changeover rather than standing in the sun out of habit, keep your drinks as cold as you can for as long as you can, and treat those ninety-second breaks as precious cooling windows rather than dead time. The pros do not waste a single one of them, and neither should you.

Dress like you mean it

What you wear matters far more in the heat than most weekend players ever consider. Light colours reflect the sun where dark ones absorb it; loose, modern moisture-wicking fabrics pull sweat off your skin and let it evaporate, which is how the body actually cools itself, where a heavy cotton shirt just turns into a wet, hot sponge clinging to your back. There is a reason the entire professional tour plays in featherlight technical kit and not in old cotton tees.

Your feet deserve particular thought, because they take a beating in summer. Hot courts, sweaty socks and hours of stop-start movement are how blisters and misery are made. A breathable, well-ventilated pair from a proper summer tennis shoes guide keeps your feet cooler and drier and saves you a world of pain, and a fresh overgrip — or two spare ones in your bag — solves the other great hot-weather nuisance, the racket slowly turning to soap in a sweating hand. Small things, all of them, but in the heat the small things are what decide whether you last the afternoon.

Don't just endure the heat — train for it

Here is the encouraging news buried in all the science: the human body is remarkably good at adapting to heat, if you give it the chance. The reason the pros can play in conditions that would floor the rest of us is not only talent; it is that they are heat-acclimatised, their bodies tuned by repeated exposure to start sweating sooner, sweat more efficiently and hold a lower core temperature under the same load. Crucially, this is something a normal body learns too, usually over a week or two of gradually building up activity in the heat rather than throwing yourself into a brutal session on the first hot day of the year.

That gradual, structured build-up is exactly where a bit of dedicated off-court conditioning pays for itself. Easing your body into summer fitness with a structured tennis-conditioning program — building the engine and the resilience before you ask it to perform in the heat — is what turns a sweltering afternoon from an ordeal into something you can actually enjoy (use the code SERGEI for 10% off). Prepare for the heat in advance and it stops being your enemy; ignore it and it will find you out on the first hot Saturday in July.

Play smart: when to play, and when to stop

After all the gear and the science, the oldest wisdom is still the best: do not play in the worst of it if you do not have to. The professionals are paid to walk out at high noon; you are not. Schedule your summer tennis for early morning or the cool of the evening, dodge the savage midday window when the sun is directly overhead, and you sidestep the bulk of the danger before it begins. There is no medal for choosing the hottest hour of the day.

And learn the warning signs, because heat illness is genuinely dangerous and it can escalate frighteningly fast. Dizziness, nausea, a headache, clumsiness, confusion, the chills, or — most alarming of all — suddenly stopping sweating when you should be pouring with it: any of these means you stop, full stop. Get into shade, get fluids in, cool the body down, and do not let pride or a tight scoreline talk you into one more game. The culture of toughing it out has put even elite, supremely fit professionals in real medical danger. For the rest of us, on a Sunday, against a mate, with nothing on the line but bragging rights, pushing through heat illness is not brave. It is just a bad, and occasionally a very serious, idea.

The ones who feel it worst

One more thing, because it matters and almost nobody mentions it: heat is not an equal-opportunity opponent. It comes for some bodies far harder than others, and if you play tennis with children, or you are coming to the game later in life, the warnings above apply to you twice over.

Children are especially vulnerable. They carry a larger skin-surface area relative to their body mass, which means they soak up heat from a hot court faster than an adult does; they sweat less efficiently, so they cool themselves less well; and they are far less likely to notice the danger or to stop and drink when they should. If your kids are out on a baking court, you are the one who has to ration the breaks, push the water and call time — they will not do it for themselves until it is already too late.

At the other end of life, the body's heat defences quietly fade with age. Older players register thirst less reliably, sweat a little less freely and shed heat more slowly — which means the cheerful sixty-something who has just taken the game up for the health and longevity that tennis is famous for needs to be more careful in the heat, not less. None of this is a reason to keep anyone off the court. It is simply a reason to carry more water, take more shade, and stick to the cool hours — for the youngest and the oldest among us most of all.

The last word

Tennis in summer is one of the genuine pleasures of the sporting year — the long light, the warm evenings, the feeling of a clean strike on a still night. The heat only ruins it if you let it catch you unprepared. Drink before you are thirsty, guard your skin and your eyes, cool the neck at every changeover, dress light, build your body up to the conditions rather than ambushing it, and play in the kinder hours of the day. Do that, and the same sun that has the best players in the world cramping and quitting on television becomes nothing more than a pleasant warmth on your back.

The pros are not superhuman out there. They are simply prepared, down to the last ice towel — and on this particular opponent, preparation is the whole game. Beat the heat, and the summer is yours.

Sources

• Sky Sports and ATP Tour: new extreme-heat rule effective from 2026, based on Wet Bulb Globe Temperature (10-minute break at WBGT 30.1°C; play halted above 32.2°C)
• ESPN and Euronews: ATP heat rule for men's matches mirrors the long-standing WTA policy; Grand Slam and Olympic heat policies
• USTA, "Beat the heat": cooling and hydration guidance for tennis players
• Peer-reviewed research (PMC) on heat stress, hydration and cramping in match-play tennis: ~2% dehydration before thirst; core-temperature and heart-rate effects of fluid loss; sodium and muscle cramping
• Reporting on heat incidents in professional tennis, including Jannik Sinner's cramps and Novak Djokovic's conditions-related distress

Photo: A player battling in the sun, US Open / robbiesaurus / Wikimedia Commons / CC BY-SA 2.0