ATP 2026 Heat Rule: WBGT Triggers, 10-Minute Cooling Breaks, and Australian Open Prep

The rule in plain English

Starting in 2026 the ATP will use Wet Bulb Globe Temperature, a heat stress index that blends air temperature, humidity, sun, and wind, to decide when cooling breaks occur and when play pauses. When the Wet Bulb Globe Temperature hits 30.1°C during the first two sets of a best of three singles match, either player can request a supervised 10-minute cooling break at the end of set two. If it exceeds 32.2°C, play is suspended. The aim is safety first, with clarity for players, coaches, officials, and fans. You can read the official summary in the ATP heat rule effective from 2026. For more applied context on thresholds and tactics, see our WBGT thresholds and tactics primer.

Why this matters for your planning: the game will have predictable cooling windows. Matches that reach one set all in extreme conditions will include a defined stop. That pause changes momentum, recovery, and equipment choices. Training plans should prepare athletes to use that 10-minute window as a performance advantage rather than an emergency bandage.

Why Wet Bulb Globe Temperature changes tempo

Heat is not just hot air. Athletes bleed energy through sweat and airflow over the skin. High humidity blunts that cooling. Direct sun adds radiant load that spikes body temperature even when the air does not feel outrageous. Wet Bulb Globe Temperature wraps those factors into a single number that correlates well with rise in core temperature and dehydration rate.

Tempo in heat is about controlling peaks. Spikes in heart rate and core temperature often come from three things: long high speed rallies, extended deuce games with repeat explosive efforts, and quick turnarounds between points that compress breathing. The new rule gives one planned release valve. The rest of the day still belongs to the player who manages between point recovery and shot selection to avoid those spikes.

Between point breathing and reset routines that work

Between points you get roughly 25 seconds. Use that time deliberately to drop heart rate, clear carbon dioxide, and lower perceived exertion.

Try this simple three step reset routine:

1. Spot and walk: As soon as the point ends, find a landmark beyond the baseline such as the back wall or a corner of the stands. Walk toward it slowly while twirling the racquet to keep your forearm relaxed. This small ritual prevents you from staring at the scoreboard and builds separation from the last point.

2. Breathe to recover: Do two cycles of nasal inhale for four seconds, brief hold for two, then long mouth exhale for six. Aim the exhale downward through slightly pursed lips. If the point was especially long, add one extra long exhale. This ratio favors vagal tone and a measurable drop in heart rate without lightheadedness.

3. Cue to commit: Right before the serve or return, say a short cue in your head. Servers might use “first target, legs up.” Returners might use “split, see, step.” Keep it five words or fewer. This reduces cognitive load and keeps your pre point plan crisp.

Towel use is part of the reset. In heat, use an ice towel briefly over the back of the neck or forearms rather than the face. The neck and forearms cool the blood without numbing the facial muscles that you rely on for breathing control.

Practice cadence. Set a metronome at 50 to 55 beats per minute during practice changeovers and learn the rhythm of inhale on one beat and extended exhale over two beats. Then remove the metronome and reproduce the cadence by feel during point play.

Pre cooling and hydration that actually works

There is no single magic drink. There is a simple process you can repeat.

Two to three hours before a likely hot match:

• Drink 500 to 700 milliliters of a light electrolyte drink at about 3 to 4 percent carbohydrate. This primes total body water without gut slosh.
• Eat a small salty snack if you tend to be a heavy sweater. A modest sodium bump improves fluid retention.

Forty five to sixty minutes before play:

• Use an ice vest for 10 to 15 minutes if available. If not, hold forearms in cool water for five minutes and finish with a slushy drink. The goal is to drop skin temperature and slightly cool the core without shivering.
• Prepare two bottles per set: one chilled electrolyte at 3 to 5 percent carbohydrate with 400 to 700 milligrams of sodium per liter, one plain water. Mark sips by game number so you do not forget under stress.

During play:

• Between points, one small sip is enough. At changeovers, take two to three longer sips. If your gut feels heavy, switch to more plain water for a game or two while keeping small electrolyte sips.
• Use ice towels on neck and forearms only for 10 to 20 seconds at a time. Long application can trick the skin into vasoconstriction, which is counterproductive.

During the 10 minute cooling break when triggered:

• First minute: step into shade and sit on a cool surface if possible.
• Minutes 1 to 4: cool shower if available or aggressive ice towel rotation on neck, forearms, then thighs. Coaches should handle towel swaps.
• Minutes 4 to 6: change to a dry shirt, dry socks, and fresh overgrip. Heat plus sweat destroys friction. Fresh socks reduce blister risk during the next sprint phase. Replace sweatbands.
• Minutes 6 to 8: drink 200 to 300 milliliters of chilled electrolyte. Avoid chugging plain water in large volume, which can dilute plasma sodium.
• Minutes 8 to 10: confirm the first two plays of the next game. Visualize serve patterns or return position. Walk out early to avoid a rushed first point.

After the match, weigh yourself if you can. Every kilogram of body mass lost roughly equals a liter of fluid deficit. Replace about 150 percent of that over the next two to three hours with a mix of water and electrolytes while eating normally.

Pace management under the clock

Heat rewards clarity. You are not trying to play less tennis. You are trying to remove spikes in effort while keeping pressure high.

Serving:

• Raise first serve percentage by aiming more body serves and hitting bigger targets. Body serves save your legs on the first ball and set up predictable third shots.
• Use a deliberate walk back between first and second serves to restore breathing. It takes three seconds. That three seconds pays back later in the game.

Returning:

• Move your return position back a half step in the hottest phases to extend reaction time without giving up court. It reduces emergency sprints.
• Shift the target of neutral returns toward deep middle. Deep middle limits the opponent’s angles and reduces your side to side running.

Rallies:

• Favor patterns that end at the net when the ball lands short. Two balls to a corner then a firm approach through the middle forces a pass under pressure without extra running.
• Use the drop shot sparingly but purposefully. Best timing is after two heavy crosscourts that push the opponent behind the baseline, not from a static position.

Changeovers:

• Sit, feet slightly elevated on your bag. Two deep breaths with long exhale first, then sip, then coach cue, then stand with 20 seconds left. This order avoids the rushed stand that spikes heart rate right before the next point.

Heat smart equipment choices

• Clothing: light colors, breathable fabrics, and mesh panels under the arms. Microfiber shirts that stay light when wet beat cotton. Bring at least three shirts for best of three in heat.
• Hats and glasses: a ventilated cap with a dark under brim cuts glare and lowers squinting. High contrast lenses reduce eye strain and make tracking in haze easier.
• Grips and wristbands: rotate a dry wristband every set. Change overgrips at the cooling break and again if you feel twisting. Consider a thin rosin bag tucked in the bag for emergencies, but use sparingly to avoid slick residue.
• Shoes and socks: hot courts soften outsoles. If you slide, check for early edge wear and retie with a firm heel lock. Dry socks at the cooling break reduce blister risk.
• Strings: in peak heat the ball flies. Lower tension by one to two pounds to enlarge the sweet spot and reduce the effort needed to generate depth without overhitting.

Drills that rehearse Wet Bulb Globe Temperature match flow

Build these sessions into the next two weeks so your player arrives in Australia with a heat plan they have already used.

1. Cooling break simulation set

• Format: play two short sets to four with no ad scoring. If the local Wet Bulb Globe Temperature reaches 30°C or higher, insert a mandatory 10 minute break after set two. If you do not have a Wet Bulb Globe Temperature device, practice the break anyway.
• Objective: rehearse the exact sequence for those 10 minutes. Time each step. Coaches should practice the handoff of ice towels, shirt change, socks, and overgrips. Players should practice a 90 second visualization before return to court.

2. Serve tempo ladder

• Format: 12 first serves per minute for three minutes, rest one minute, then 10 per minute for three minutes, rest, then 8 per minute for three minutes. Repeat twice.
• Objective: learn the breathing and walk back rhythm that keeps heart rate stable while maintaining first serve percentage.

3. Short ball finish circuits

• Format: basket feed two deep crosscourts, then one short middle ball to finish either with a firm approach down the line or touch drop. Ten reps each side for three sets.
• Objective: practice point construction that limits lateral sprints and ends points with forward movement.

4. Return plus two pattern with middle targets

• Format: return deep middle, rally ball deep middle, then a directional ball to open space. Ten sequences per side for three sets.
• Objective: remove angles until you are in control so you are not the one doing emergency defense in heat.

5. Breathing under fatigue

• Format: 90 seconds of split step and shuffle shadowing, then 25 seconds of the 4 2 6 breath pattern. Repeat six times.
• Objective: teach the nervous system that long exhales are the default, even when legs are heavy.

6. Gear swap practice

• Format: every 30 minutes, stop for 90 seconds to change wristbands and regrip while keeping heart rate down with two long exhales and a sip. Practice pulling a dry shirt over damp skin quickly.
• Objective: make the gear side of heat management automatic.

What this means in January: United Cup and Australian Open

The Australian summer swing starts with the United Cup from January 2 to January 11, 2026 in Perth and Sydney, then the Australian Open main draw begins on Sunday January 18, 2026 in Melbourne. For team dynamics, travel, and acclimation specifics, see our United Cup 2026 guide.

United Cup

• Perth sessions are staged at RAC Arena, a fully enclosed indoor venue. That sharply lowers radiant heat load and stabilizes on court conditions. Players can expect less direct sun stress but still need hydration and breathing discipline for long ties.
• Sydney’s Ken Rosewall Arena has a fabric roof that provides full shade and improved airflow. On very hot days the venue can still feel warm, but sun exposure is reduced. Sessions can run day and night, so plan meals and hydration to cover early starts and late finishes.
• Tactical edge: the new ATP cooling break applies to best of three singles if the Wet Bulb Globe Temperature threshold is hit during the first two sets. Your rehearsal should include a cooling break routine even when playing in shade, so the first time you do it is not during a live tie.
• Scheduling tip: teams that advance from Perth travel to Sydney with a rest day. Use that day for a light hit in similar conditions and a 20 minute cooling break walk through with the full kit.

Australian Open

The Australian Open runs its own heat policy based on a five point Heat Stress Scale, which uses live measurements and a tennis specific algorithm to guide breaks, roof closures, and suspensions. For background on the system see the AO Heat Stress Scale overview. In practice this means you may play in open sunshine on an outside court during a day session, step under a closed roof at night, or see play paused on outside courts if the index reaches the top of the scale.

• Tactical edge on outside courts: simplify patterns, serve to bigger targets, and attack short balls to finish forward. Deep middle remains your friend until you earn a short reply. If the Heat Stress Scale forecasts a rising index for your time slot, plan for more first strike tennis early, before conditions peak.
• Night sessions under roof: the ball can feel heavier and rallies stretch. Rehearse a slightly higher net clearance baseline pattern and build patience, then use front court finishes when you get a sitter.
• Equipment rotation: outside courts mean more sweat. Fresh socks and overgrips at every break matter. Under roof at Rod Laver Arena or Margaret Court Arena you may not need as many changes, but still schedule them to keep grip friction high late in sets.
• Mixed doubles and singles load: if your player is in both events, do the math backward from likely finish times. A late night mixed doubles slot can collide with next day singles. Use a short pre sleep snack with electrolytes and plan a cold shower plus two minute breathing session to lower core and heart rate before bed. To sharpen late set poise, fold in this two-week tiebreak microcycle.

A coach’s checklist for January

• Pack for the plan: two cooling towels, small spray bottle, two sets of wristbands per set, three shirts, spare socks in zip bags, four overgrips, rosin bag, ice vest if available, electrolyte powder, and a collapsible fan for the bench if allowed.
• Rehearse roles: who handles towels, who tracks sips and shirt changes, and who runs the two minute breathing drill on the sideline timer.
• Real time decisions: if the Wet Bulb Globe Temperature threshold is approaching and you have split sets, consider saving tactical wrinkles for the first two games after the break when the opponent has cooled but may be mentally flat.
• Communication: agree on a single phrase that means shift to deep middle neutrality for three rallies to reset heart rate. For example, “middle lock.”

How OffCourt can help

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 OffCourt.app environment you can save a heat plan with the exact pre cooling routine, hydration pack list, and between point breathing cadence. You can also log simulated cooling breaks and see which combinations of drink mix and timing produce the best late set hitting quality. Coaches can push the drills above to an athlete’s calendar and attach the gear checklist so nothing gets forgotten in the rush.

The bottom line

The new Wet Bulb Globe Temperature rule does not just protect players. It codifies match tempo in the heat. The athletes and coaches who practice that tempo will keep clarity when everyone else is guessing. Build your 10 minute cooling break routine now, train your breathing between points, simplify patterns to control spikes in effort, and pack gear that stays reliable when soaked. Do those four things, and January in Australia becomes a predictable challenge.

Set your next two practices to include one simulated cooling break, one serve tempo ladder, and one short ball finish circuit. Save the routine in OffCourt, assign roles, and arrive in Perth, Sydney, or Melbourne with a heat plan you trust. Then use the sun as a competitive advantage instead of a reason to wilt.