Racehorses Forced to Race in Extreme Heat and Humidity
Multiple instances of heat stress, respiratory distress and poor post-race recovery are recorded in Stewards reports on every hot and/or humid race day in Australia.
However, while the Australian Veterinary Association clearly states that heat stress should be prevented, racing is prioritising treating heat stressed horses rather than preventing them from suffering in the first place.
Heat stress is a serious welfare issue for horses as it can cause severe illness and death. The horse’s brain is very sensitive to overheating, and neurological signs are frequently observed in racehorses on hot race days, particularly irritability, head shaking and random kicking. Heat stress symptoms can progress to disorientation, unpredictable lunging forward, ataxia and collapse.
Human athletes have the privilege of choosing whether or not they will perform on any given day, with consideration of their body’s ability to tolerate the weather conditions, and in the knowledge that intense exercise drastically increases body temperature in a matter of minutes. They know that hot and/or humid conditions pose a high risk of being unable to dissipate excess body heat through sweating.
Racehorses on the other hand, are not afforded the same privilege of choice. Punters are still happy to go to the races on hot days, and cancellation of racing events due to weather conditions is costly and disruptive to everyone involved in race day operations. The horses, however, are left to pay the price.
Heat Stress in Racehorses
Heat stress in racehorses is different to heat stress in horses used for equestrian sports. The intensity of the exercise in racing can rapidly lead to hyperthermia, which causes reduced blood flow and oxygen to the horse’s brain. This condition in thoroughbred racehorses in Australia is known as Exercise-Induced Heat Stress Syndrome or EHI, “Exertional Heat Illness”.
EHI occurs when a horse is prevented from dissipating the excess heat they generate during a race. This can be due to high ambient air temperature and/or humid conditions, often combined with exposure to direct sunlight and lack of airflow.
The prevalence of EHI in Australian racehorses is difficult to determine because, 1), the racing industry does not publish specific data on it and 2), because incidents of heat stress are often disguised in Stewards reports as something else, such as “poor recovery” or “slow to recover”, or is not reported in full or at all in the Stewards reports.
A possible explanation for racing’s failure to accurately report heat stress in their Stewards reports could be due to a conscious decision only to report incidents of heat stress that have progressed to the most severe level.
Current Hot Weather Policies in Racing
The Australian Veterinary Association (AVA) policy on heat stress states that those responsible for making horses work in hot weather should take appropriate steps to prevent heat stress, have resources available to treat heat stress and have policies in place for when competitions must be cancelled due to extreme weather.
However, there are no consistent rules that prohibit horse racing in Australia above a specific temperature. The hot weather policies also vary vastly from state to state, and most are vague and unclear.
In some Australian states, racing is using a ‘wet-bulb globe temperature’ (WBGT) device to determine the risk of heat stress. By including other factors such as humidity, it is considered more accurate than only relying on the basic ambient temperature, which is measured in the shade.
When the WBGT measurement is over 32, some state racing authorities consider the heat to be extreme, and they must enable their hot weather policy. Racing has decided that they can then choose to modify, postpone or cancel an upcoming racing event. In reality, however, postponement or cancellation rarely occurs.
Instead, racing opts for “modifying” the event by changing race start times to avoid the hottest part of the day, while ignoring the reality that horses could still be travelling (sometimes for several hours to or from the races) in peak heat times. Racecourse staff will then arm themselves with water buckets and icebags in anticipation of horses suffering in the heat, instead of preventing their suffering by postponing the races to a cooler day.
Individual state racing heat policies or guidelines as of December 2025
Northern Territory
In the Northern Territory, racing has decided it is ‘unrealistic’ to set an upper limit for temperatures and humidity to determine if races should be modified, postponed or cancelled. Instead, it’s at the Stewards’ discretion. Racehorses are already suffering from the hot and humid climate in NT, where many develop anhidrosis, which impacts their ability to sweat.
South Australia
In South Australia, racing uses both ambient temperature and WBGT. In the event the forecast/actual temperature for a race day is 38°C or above, or 32°C (WBGT) “sun” or above, Stewards must take advice from the Veterinary Surgeon/s in considering whether to proceed with or modify the event. It is not specified what “modifying” would be.
Queensland
In Queensland the racing industry considers temperatures above 35 degrees “extreme”. Although it is not clear from their heat policy if this is the ambient temperature or a WBGT measurement. Nor is it clear what measures they will take when the temperature does reach extreme.
Western Australia
In Western Australia racing do not make use of the WBGT calculator to determine when race days should be modified, postponed or cancelled. Instead, they have set the ambient temperature of 38 degrees Celcius as their threshold for when they must enable their hot weather policy. There is no set level of humidity stated to be considered.
New South Wales/ACT
Racing NSW uses both WBGT and ambient temperature. When the forecast or current ambient temperature for a race day is 38°C or above, or the WBGT shade is 28°C or above, their policy states Stewards must take advice from the official veterinarian/s in considering whether to proceed or modify the program for that race meeting.
Tasmania
In Tasmania, which is also generally the coolest state in Australia, racing uses both ambient temperature and WBGT. Tasmania is the only state with a mandatory policy to not only modify but postpone or cancel race meetings on days with a forecast of 38-degree Celcius ambient temperature or a WBGT measurement of 32.
Victoria
In Victoria, instead of a policy, racing has guidelines for racing in hot weather. Racing Victoria considers a WBGT measurement of over 32 as “high risk”. If high risk conditions are identified, they will give consideration to modifying, transferring, or abandoning the race meeting or official trials. It is not specified what “modifying” would be.
Problems in Relying on WBGT
Although the WBGT is recommended as a heat stress index, it does not account for the metabolic heat generated by physical activity. It can also be deceiving in the way that measurements may still be below “extreme”, if some indicators are low enough to bring down the total measurement. As such, we see horses being raced in sweltering heat because the WBGT is still just below what racing considers extreme.
The accuracy of the heat stress risk based on the WBGT is also reliant on the horses being well hydrated and having a sufficiant level of salt and electrolytes for the task ahead.
This can be difficult to achieve in horseracing, as many racehorses are already sweating heavily upon arrival at the racetrack from the travel alone. Even more disturbingly, it is also still a fairly common practice to withhold water before a race, in the false belief that it will reduce the risk of exercise-induced bleeding from the lungs.
While most racecourse facilities include some shaded areas for the horses when they arrive, few are equipped with fans and even fewer with electric air-conditioning. These facilities, however, are of no use to the horses when they are taken out onto the track to race, or when they are put back into a non-air-conditioned horse float to travel home.
The temperature inside a horse float can be up to 9.5 °C higher than the outside temperature, and the fear level of a horse in a float can cause heat stress and over-sweating, even in comfortable weather conditions.
Comparison to Equestrian Hot Weather Policy
There is an urgent need to drastically strengthen the hot weather policies in Australian racing to prevent heat stress and the suffering of racehorses forced to perform in extreme heat. Although the intensity of other horse sports is far less than racing, Equestrian Australia provide their horses with significantly better protection against heat stress:
- Once the WBGT reaches 28 (as opposed to 32 in racing), shaded areas must be used for EA competition and warm-up. This is not an option in racing as these areas are not shaded on racetracks.
- Non-grassed riding surfaces must be avoided as they radiate additional heat. This is also not an option on the many dirt and sand racetracks around the country.
- Reduce overall effort of the horses such as shorter distances or less jumping effort. Racing could, if they wanted, shorten the distance of the races, but they are unable to lessen the intensity of the effort required by the racehorses.
As such, because most of the measures in EA’s hot weather policies cannot be achieved, and are not even feasible in racing, the racing industry must introduce mandatory cancellation or postponement of races to a cooler day, and at a much lower stage than a WBGT of 32 .
Prevention of Heat Stress in Racehorses
CPR proposes that a national hot weather racing policy should include a threshold of both WBGT measurement and ambient temperature. If the racing industry wants to prevent horses suffering heat stress, mandatory postponement to a cooler day or cancellation of the racing event must be implemented.
CPR proposes that as a minimum, all state racing authorities should implement a policy that prohibits racing on days with a forecast of 38°C ambient temperature or a WBGT measurement of 28.
Racehorses are suffering enough on race days as it is. It is time that racing began working on preventing horses from suffering heat stress, rather than expecting it and treating it after it has occured.
HELP ADVOCATE FOR STRICTER HEAT POLICIES IN RACING
Please use the form below to email Racing Australia and state racing authorities in NSW/ACT, VIC, SA, WA, QLD, TAS and NT, and urge them to take urgent action to prevent heat stress in racehorses. You can edit and personalise the email subject and body to have more impact or leave as it is. THANK YOU FOR TAKING ACTION!
