Coach's Guide to Sports Medicine Australia Extreme Heat Guidelines 2025

Under Moderate risk the SMA guidelines recommend increasing the frequency and/or duration of rest breaks:

• Training sessions: a minimum of 15 minutes of rest for every 45 minutes of practice.
• Matches: extend naturally occurring breaks (e.g. half-time) by about 10 minutes. This is effective for sports such as soccer and rugby and can be applied to others such as field hockey.
• Extra breaks: add breaks not normally scheduled, for example 3 to 5 minute "quarter-time" breaks midway through each half of a football or rugby match, or an extended 10 minute drinks break every hour of a cricket match or after the second set of a tennis match.
• Continuous play with no scheduled breaks: the course or play duration can be shortened.
• During all breaks: everyone should seek shade (portable sun shelters if there is no natural shade) and water should be freely available.

At Extreme risk the SMA guidelines say suspension of exercise or play should be considered. If play has commenced, all activities should be stopped as soon as possible. The SMA hot weather page says to delay or cancel play if conditions reach Extreme risk levels.

When play stops:

• All players should seek shade, or a cool refuge in an air-conditioned space if available.
• Active cooling strategies should be applied.

Hydration and clothing (listed under Low risk):

• Drink regularly throughout exercise, enough to offset sweat losses, but avoid over-drinking.
• Before exercise, drink 6 ml of water per kilogram of body weight every 2-3 hours (for a 70 kg person, 420 ml every 2-3 hours).
• Choose lightweight, breathable clothing with extra ventilation, remove unnecessary clothing or equipment, and reduce the amount of skin covered.

Active cooling (listed under High risk), applied during scheduled and additional rest breaks, or before and during activity if play is continuous:

• Drink cold fluids and/or ice slushies before exercise starts (cold water and ice slushies during exercise are less effective for cooling).
• Submerge arms or feet in cold water.
• Water dousing: wet the skin with cool water using a sponge or spray bottle, as evaporation is the most effective cooling mechanism in the heat.
• Ice packs or a damp towel filled with crushed ice around the neck.
• Electric (misting) fans, especially combined with a water misting system.

During all breaks, everyone should seek shade. If natural shade is not available, portable sun shelters should be provided, and water freely available.

The SMA Extreme Heat Risk and Response Guidelines (2025) say it is currently unclear whether heat stress risk is truly elevated in children.

The SMA hot weather page adds that children aged about 10 to 16 are not at greater physiological risk of heat illness than adults, but may respond differently to heat behaviourally, for example by not recognising warning signs. It says organisers should err on the side of caution, and that future updates are expected to add junior-sport adjustments.

If hot weather is forecast, in the preceding 24 hours:

• Avoid extended strenuous exercise that will substantially pre-elevate core temperature.
• Be well hydrated: drink water regularly the day before and drink 500 ml of water 1-2 hours before play begins.
• Players used to multiple cups of coffee a day should avoid high caffeine doses in the hours leading up to play.
• Immediately before exercise, pre-cool by drinking cold water or an ice slushy, immersing the lower half of the body in cold water, or wearing an ice vest.
• Paracetamol does NOT lower the body temperature response to exercise and is not recommended to reduce heat stress risk.

In the days and weeks before (acclimatisation):

• Expose yourself daily to the conditions you will play in for 45-90 minutes a day, for a minimum of 5 and preferably up to 14 consecutive days.
• Exercise at the same perceived effort, so the absolute level of work increases as you adapt.
• If protective equipment is usually worn, wear none for the first 3-4 days, then gradually increase equipment levels each day.
• Do not assume extra protection from acclimatisation if exercise intensity and exposure frequency are low.

The SMA guidelines say even the fittest athlete can be affected, but certain people are especially vulnerable:

• People aged over 65, especially if unfit (risk is generally greater with more advanced age)
• People with heart or kidney disorders or disease
• People recently sick with a fever
• People taking prescription medications that impair sweating
• People with a reduced ability to respond to heat behaviourally, e.g. due to mental health challenges or substance abuse
• People with very high body fat
• People who have recently (in the past week) arrived from a cold climate

The SMA guidelines say to watch for heat-related illness whenever sport is played in the heat, whatever the risk level.

Heat exhaustion/syncope

• Feels: headache, dizziness, weakness, nausea, vomiting.
• Signs: fainting, increased heart rate, decreased blood pressure, core temperature usually below 40°C, and no brain symptoms.
• Immediate management: move to shade and cool, remove as much clothing as possible, remove protective equipment (e.g. helmets, pads), apply lots of water to the skin, give oral fluids, lie the person on their back with legs elevated, and watch for worsening.

Exertional heat stroke (a medical emergency)

• Brain symptoms including confusion and agitation, which can develop rapidly.
• Signs: confusion, unsteadiness, aggressive or irrational behaviour, altered level of consciousness, seizures or coma, increased heart and breathing rate, decreased blood pressure, core temperature usually above 40°C.
• Immediate management: ABC (airway, breathing and circulation), aggressively cool the body with ice and water (e.g. an ice or cold water bath), call an ambulance, and continue cooling during transfer to hospital: "Cool first, transfer second".

The SMA Sports Heat Tool page also says any collapse in hot conditions should be treated as potential heat stroke, and an ambulance called immediately.