Heat-Proof Tennis at 40°C: A Practical Playbook from the 2026 Australian Open

The 40°C week that turned Melbourne into a heat lab

The 2026 Australian Open delivered a clear message. If you want to win modern hard-court tennis, you need a plan for extreme heat. Multiple afternoons pushed toward 40°C. Matches on outside courts were paused. Arena roofs closed and reopened as the Heat Stress Scale climbed and fell. Some players came out of stoppages sharper. Others wilted.

Heat did not just make matches uncomfortable. It changed the sport’s tactical geometry and the day’s energy budget. In hot, heavy air the ball slows fractionally and rallies tax the legs sooner. Roof closures remove wind and shift the advantage toward first-strike patterns. Stoppages break rhythm and spike nerves. For more context on ball flight and decision-making in these conditions, see how heat changes pro tactics.

This article turns those lessons into a practical playbook you can use for the next heat wave on hard courts.

Build a modern heat plan

A good plan does four jobs:

1. Keeps your core temperature and blood volume in the safe, high-performance range.

2. Shrinks the cost of each point by controlling tempo and shot selection.

3. Trains your body to handle heat weeks before you arrive at the event.

4. Anticipates stoppages and roof changes so they help you rather than hurt you.

Use the steps below, then adjust after your first heat match based on weigh-ins and how you felt.

1) Pre-hydration and sodium: arrive with a full tank

Think of your blood volume like the coolant in a race car. Show up low and you overheat early. Show up full and you can push longer.

• The day before: Eat normally, include salty foods at meals, and drink to thirst throughout the day. Add an extra 500 to 700 milliliters of fluids with dinner if you typically wake up light. Avoid alcohol.
• Morning of match: Check your first urine of the day. Pale straw suggests you are on track. Dark apple juice suggests you need catch-up fluids and sodium at breakfast.
• Three to four hours before first ball: Drink 5 to 7 milliliters per kilogram of body mass of a drink that contains electrolytes and 6 to 8 percent carbohydrate. For a 60 kilogram junior, that is roughly 300 to 420 milliliters.
• Sixty minutes before walk-on: If your urine was dark in the morning, or you sweat heavily, add another 2 to 3 milliliters per kilogram.
• Sodium starting point: Begin with 500 to 700 milligrams of sodium per liter of fluid on heat days. Heavy, salty sweaters may need more. If you finish a hot match with salt crust on your hat or shirt, or if you cramp late despite drinking, you are a candidate for a higher sodium plan.
• Carbohydrate during play: Target 30 to 60 grams per hour in matches that run longer than 60 to 90 minutes. That is two standard sports gels per hour or a bottle of 6 to 8 percent carbohydrate drink plus one gel.
• Hyponatremia guardrails: Never force fluids beyond thirst if you are gaining weight during play. Replace most, not all, sweat losses during the match. Finish the job afterward.
• Post-match rehydration: Aim to drink about 150 percent of the body mass you lost within four to six hours, with sodium in the drink or mixed into food.

Coach’s tip: Pack your player’s bottles the night before. Label them by set so you can pace intake rather than chugging early and fading later.

2) Cooling protocols that actually move the needle

Cold that touches the skin is not automatically performance cooling. The goal is to pull heat from blood flowing near the surface and to reduce sweating cost without causing a shiver response.

• Ice towel recipe: Wring a towel in an ice-water cooler, then fold it lengthwise and drape it across the back of the neck so it touches the big vessels that feed the brain. Rotate a fresh towel every changeover in extreme heat.
• Palm and cheek cooling: Holding an ice-cold bottle against your palms or gently against your cheeks for 20 to 30 seconds during changeovers cools blood efficiently because those areas have high blood flow and specialized heat exchange surfaces.
• Neck first, then head: A cap with ice under it can help, but the neck wins on effect per second.
• Slushy strategy: If you tolerate it, a half bottle of ice slush at every second changeover is internal cooling and hydration in one. Practice this so your stomach knows what is coming.
• Shade matters: Use the chair’s shadow, cover with a light towel between points if needed, and sit rather than stand on changeovers.
• Recovery between suspended sessions: If play is paused, your first move is to get cool, not to stretch on the court. Find a cooled area, use ice towels and a fan, and sip fluids with sodium. If you have access to a cooling vest, this is the moment to use it.

Parent’s tip: Carry two small, soft-sided coolers. One is for ice towels and slush. The other is for bottles and gels. This keeps consumables clean and easy to reach.

3) Serve and return tempo: buy energy with seconds, not slogans

The heat rewards the player who spends energy slower. Use the serve clock as a tool, not a threat. For a pro-level example, study Sinner’s serve-clock playbook.

• Take your legal time: You get up to 25 seconds between points. Use 20 to 24 seconds after long rallies. Use 18 to 20 seconds after short points to keep rhythm without rushing.
• Routine that cools: Bounce count is not the point. Breath is the point. Commit to one slow nasal inhale and one long exhale before the serve. Towel only when you need it. The goal is to leave the line ready, not rushed.
• Second-serve simplicity: Reduce double faults in the heat by choosing one trusted second-serve target on each side. Simplicity lowers cognitive load and heart rate.
• Return positioning: Move back half a step in heavy heat to buy reaction time. Against big servers indoors under a closed roof, shift forward on second serve to take time away.
• Momentum after stoppages: When play resumes, hit two safe first serves and one crosscourt return to re-establish timing. You are not trying to win the match on the first point back.

Coach’s tip: Rehearse a 30-second changeover routine in practice. The stopwatch is part of training. Players learn they can do more cooling than they think without rushing.

4) Tactics that shrink the cost per point

On very hot days, you win more by asking the court to work for you.

• Target the T on first serves to shorten lateral movement on the next ball.
• Attack second serves with depth rather than pace. Deep returns force shorter, more vertical swings from the opponent.
• Construct serve plus one or return plus one combinations that end by shot four. Practice these patterns on command.
• Bring the net forward as a rest tactic. Two steps to finish a high ball saves you ten steps of rallying.
• Use the drop shot when the opponent is visibly heavy-legged, then look for the lob over the first recovery step. Make their feet change direction.
• Spin for air time: Heavier topspin buys you an extra half beat to breathe and recover balance.

5) Practice simulations: acclimate before you land

Heat readiness is built, not borrowed. Plan at least 10 to 14 days of heat acclimation before a hot event.

• Phase 1, days 1 to 4: Daily 60 to 90 minutes of moderate work in a warm environment. That can be late-morning outdoor hits, a stationary bike in a heated room, or light layers during practice. Finish with 10 to 20 minutes of passive heat exposure such as a warm bath or sauna if tolerated. Drink to thirst and note perceived effort.
• Phase 2, days 5 to 10: Add one high-intensity set of tennis per day in the heat. Keep total work under two hours. Introduce competition drills where players must manage the serve clock under fatigue.
• Phase 3, days 11 to 14: Two match simulations in the heat, best of three sets, full changeovers. Use your cooling kit exactly as you would in a tournament. Weigh before and after to learn your sweat rate and tailor fluids.
• If you live in a cool climate: Use layers, indoor courts with heaters, or post-practice sauna to mimic heat stress. The goal is internal body temperature, not ambient bragging rights.
• Red flags to stop a session: Chills, dizziness, confusion, loss of coordination, or goosebumps in the heat. Stop, cool, and reassess the next day.

Off-court training is the most underused lever in tennis. OffCourt unlocks it with personalized physical and mental programs built from how you actually play. Use it to schedule your acclimation blocks and to track your weigh-ins, fluids, and sodium so your plan becomes automatic.

Master the stoppage: suspensions and roof closures

Melbourne reminded everyone that the match you start is not always the match you finish. Conditions can flip in minutes. Treat stoppages and roof moves as chances to reset. To sharpen your process, practice the 90-second tennis reset before your next event.

If play is suspended in five minutes

• Signal your team to prep ice towels and a slush.
• Finish the current game with simple patterns. Do not gamble to avoid the stoppage.
• In the locker area, begin cooling first. Do not start stretching until your breathing and heart rate drop.
• Take small sips of fluid with sodium. Do not chug. Aim for 200 to 300 milliliters in the first 10 minutes.
• Set a timer so you have a short activation five minutes before the projected restart: band walks, shadow swings, and two short sprints in a hallway.

If the roof closes mid-match

Indoor conditions remove wind and increase serve consistency. The court often plays a touch faster through the air.

• Serving plan: Aim more first serves down the T. Confirm your toss is not drifting in suddenly still air.
• Returning plan: Slide one step forward on second-serve returns. The ball will not be moved by gusts, so you can be more aggressive with feet planted.
• Equipment check: If you strung tight for daytime heat, be aware the ball may jump a bit more indoors. Commit to higher net clearance for the next two games, then reassess.
• Mindset: Expect a two-game feel-out period. Simplicity beats cleverness here.

Coach’s tip: Keep a laminated roof card in the bag with the four adjustments above. During the changeover after closure, show it, say one sentence per line, and let the player breathe.

Know your numbers: sweat rate and sodium checklist

Personalization beats formulas. Use this simple test to tailor fluids and sodium.

• Pre-practice weight after bathroom, minimal clothing.
• Track fluid volume consumed during a one hour hit in the heat.
• Post-practice weight after toweling off, same clothing.
• Sweat loss in liters equals body mass loss in kilograms plus fluids consumed in liters, minus urine if it was significant.
• Example: You lose 0.6 kilograms and drink 0.8 liters. Your sweat loss is about 1.4 liters per hour.
• Start with 60 to 80 percent replacement during play. In that example, target 0.8 to 1.1 liters per hour split across changeovers. Add sodium according to your plan and adjust if you cramp or feel bloated.
• Signs you need more sodium: Salt crust on clothing, persistent muscle cramps late in matches, or frequent bathroom trips despite drinking modestly.
• Signs you are overdoing fluids: Stomach sloshing, nausea without high effort, or weight gain across the match.

The hot-day bag list

• Two soft coolers: one for ice towels and slush, one for bottles and gels.
• Four to six pre-mixed bottles labeled by set, each with your target sodium and carbohydrate.
• Extra dry socks and a second shirt. Dry fabric helps cooling and focus.
• Two to four small hand towels for neck and palms.
• Electrolyte packets with at least 500 milligrams sodium each for refills.
• A simple thermometer card if allowed on site so your team can track trends.
• A printed routine card for suspensions and roof closures.

Coaches’ sideline triage in heat

• Watch eyes and gait first. Dull eyes and unsteady feet beat any heart rate number for urgency.
• Ask a simple cognitive check at changeovers if your player seems off: What was the score of the last game and where are we serving next. Slowed response is a cue to cool and simplify.
• Swap to a simpler pattern when your player’s footwork fades. Serve plus one to the body, then up the line finish. On return, deep crosscourt, then high to the backhand. This keeps spacing big and movements straight.
• If stoppage is possible, pre-stage ice towels and a slush near the tunnel. The first two minutes after a pause are the most valuable for cooling.

How OffCourt.app fits in

Off-court training is the most underused lever in tennis. OffCourt unlocks it with personalized physical and mental programs built from how you actually play. In the app you can:

• Build a two-week heat acclimation plan and get reminders for each session.
• Log pre- and post-session weights to learn your sweat rate.
• Set bottle labels and quantities for match day and print them as a checklist.
• Store your roof closure routine and have your coach pull it up at a glance.

Put it on paper this week

Heat will visit your season whether you plan for it or not. Melbourne 2026 showed how much a clear plan matters when the thermometer climbs and tournament officials start closing roofs. Do not wait for a weather app to dictate your fate. Write your plan today, test it in practice this weekend, and carry it into the next hot hard-court match. If you want help turning this into habits, use OffCourt to build and track your heat playbook. Players who treat heat as a skill, not a surprise, walk off as winners when the mercury hits 40°C.