HorseWorld’s Hot Weather Guide For Horse Owners

Hot weather can be challenging for horses, particularly when temperatures rise suddenly. While horses are remarkably resilient, prolonged periods of heat can make it harder for them to regulate their body temperature, especially when humidity is high.

Knowing how to keep your horse cool in hot weather, when to exercise, how to encourage drinking and how to recognise the signs of heat stress can all help keep your horse safe and comfortable throughout the summer.

Whether your horse lives out, is stabled, is retired or is in regular work, a few simple changes to their routine can make a big difference.

Why is hot weather dangerous for horses?

Horses rely heavily on sweating to regulate their body temperature. As sweat evaporates from the skin, it removes heat from the body. However, when temperatures rise rapidly or humidity is high, this natural cooling system becomes less effective.

This can lead to dehydration and heat stress and, in severe cases, potentially life-threatening heatstroke.

Some horses may be more vulnerable to hot weather than others, including older horses, foals, overweight horses, those with thick coats, horses with underlying health conditions and those in regular work. These horses may need closer monitoring during periods of extreme heat.

How much water does a horse need in hot weather?

One of the most important things you can do to keep your horse cool is make sure they have constant access to fresh, clean drinking water.

A typical 500kg horse drinks around 25 litres of water per day under normal conditions, but this can increase significantly in hot weather.

When horses sweat, they don't just lose water. They also lose essential salts and minerals, known as electrolytes, which help muscles and nerves function properly. That's why, alongside fresh water, salt licks and, where appropriate, electrolyte supplements can be important during hot weather.

Check troughs and buckets regularly, particularly in fields where algae, debris or warm temperatures could affect water quality.

• Dampening or soaking hay where appropriate

• Feeding wet feeds or mashes

Shade and ventilation for horses

Access to shade is essential during hot weather, but good airflow is just as important.

Natural tree shade can be particularly beneficial, providing protection from direct sunlight while allowing air to circulate. Well-ventilated shelters, stables and barns can also provide relief from the heat.

Avoid enclosed spaces with poor airflow or hot metal buildings, which can become extremely warm. Fans can be useful in stables by improving air circulation and helping sweat evaporate more quickly.

If given the choice, many horses will naturally seek out shaded areas, particularly when temperatures are high. A breezy field with natural shade can often be more comfortable than a hot, stuffy stable.

Exercising horses in hot weather

Hot weather does not necessarily mean your horse cannot be exercised, but their routine should be adapted to the conditions.

If you need to ride, early morning and later in the evening are generally preferable to the hottest part of the day. Consider:

• Reducing the intensity and duration of exercise

• Building in more walking breaks

• Allowing longer warm-up and cool-down periods

• Carrying water on longer hacks

• Avoiding unnecessary travelling

On exceptionally hot days, there is nothing wrong with giving your horse a quieter day. Groundwork, grooming, in-hand grazing or simply spending time together in the shade can be good alternatives to ridden exercise.

Your horse will not lose fitness from one or two easier days, and they may appreciate the break.

Travelling horses in hot weather

Travelling can be particularly challenging for horses during hot weather. Horseboxes and trailers can become extremely warm, even when they have good ventilation.

Where possible, travel during the coolest parts of the day and allow plenty of opportunities to offer water.

Always consider whether the journey is necessary in extreme temperatures. If you feel uncomfortably hot while standing still, your horse is likely to find exercise and travelling even more challenging.

How to cool down a hot horse

One common myth is that cold water should not be used on a hot horse. However, current research supports using plenty of cold water as an effective way to rapidly reduce a horse's body temperature.

Cold water can be applied using a hose, buckets, sponges or a portable camping shower where a hosepipe is unavailable. The water does not need to be scraped off immediately; leaving it on allows evaporation to continue helping remove heat from the horse's body.

If your horse is showing signs of heat stress, start cooling them immediately while contacting your vet for advice where necessary.

Don't forget humidity

Temperature isn't the only thing to consider when caring for horses in hot weather. High humidity can make it much harder for horses to cool themselves.

Because sweat evaporates more slowly in humid conditions, horses can be at risk of overheating even when the temperature does not appear particularly high.

Keep a close eye on your horse and be prepared to reduce exercise or change their routine when humidity is high.

Protecting horses from sunburn

Some horses are particularly vulnerable to sunburn, especially those with pink or unpigmented skin around areas such as the nose, eyes and heels.

During periods of high UV, you can help protect your horse by:

• Applying horse-safe sun cream to vulnerable areas

• Using a fly mask with UV protection

• Using a lightweight fly sheet if appropriate

• Providing access to shade throughout the day

A breathable fly mask can be particularly useful during summer, providing protection from both insects and UV rays while allowing airflow around the horse's head.

Remember that a fly mask should always be correctly fitted and checked regularly, particularly during hot weather. It should never be considered a substitute for access to shade.

Choosing summer turnout rugs and fly protection

For horses that need additional protection from flies or UV while turned out, choosing lightweight, breathable summer protection is important.

A fly rug can help reduce exposure to biting insects while also providing a degree of UV protection. Look for breathable fabrics and designs that allow air to circulate rather than trapping heat against the horse's body.

The right choice will depend on your individual horse, the weather conditions and how much protection they need. As with any rug, check your horse regularly to make sure they are comfortable and not becoming too warm.

How to recognise heat stress in horses

Most horses cope well with warm weather when sensible precautions are taken, but it is important to know what is normal for your individual horse.

Early recognition of heat stress can allow you to act before the situation becomes a serious emergency.

Signs your horse is coping well

Your horse is likely to be comfortable if they are:

• Bright and alert

• Eating and drinking normally

• Breathing comfortably

• Relaxed and responsive

Signs your horse may be struggling

Watch out for:

• Profuse or prolonged sweating

• Increased respiratory rate or heavy breathing

• Lethargy or signs of distress

• Reduced interest in food

• Seeking shade and being reluctant to move

If you notice these signs, move your horse to a cool, shaded and well-ventilated area and begin cooling them with plenty of cold water. Offer fresh drinking water and monitor them closely.

If they do not improve quickly, or you are concerned about their condition, contact your vet.

When to call your vet immediately

Seek veterinary advice if your horse shows signs including:

• Collapse

• Muscle tremors

• Weakness or stumbling

• An abnormally high body temperature

• Reluctance or inability to move

• Refusing to drink

• Confusion or unresponsiveness

• Little or no sweating despite being very hot

• Dark or brick-red gums

Begin cooling your horse while waiting for veterinary assistance. Rapid cooling can be lifesaving.

HorseWorld's hot weather tips

There are a few common misconceptions and practical considerations worth remembering when temperatures rise.

Cold water can be used to cool a hot horse

Cold water is one of the quickest and most effective ways to reduce a horse's body temperature.

Dark-coloured horses may absorb more heat

Dark coats can absorb more heat from direct sunlight than lighter coats. This does not mean every dark-coloured horse will overheat, but providing additional shade and opportunities to cool down can help.

Consider your horse's mane

A particularly long or thick mane can make some horses feel warmer, particularly on still or humid days. Loosely plaiting the mane can help improve airflow around the neck, although plaits should never be tight and should be removed regularly to prevent rubbing or discomfort.

Don't forget donkeys

Donkeys can be very good at hiding signs of illness and discomfort. During hot weather, pay particular attention to their appetite, behaviour, breathing and water intake rather than waiting for obvious signs that something is wrong.

Every horse is different

Age, fitness, body condition, workload and underlying health conditions can all affect how well an individual horse copes with heat.

Getting to know what is normal for your horse makes it easier to recognise when something has changed.

A simple hot weather routine for your horse

Adapting your daily routine can help your horse stay comfortable during hot weather.

Early morning: Carry out health checks, top up water and exercise if necessary.

Midday: Encourage horses to rest in the shade, provide soaked hay where appropriate and monitor water intake.

Afternoon: Keep a closer eye on vulnerable horses and use cooling measures if needed.

Evening: Carry out another health check, refill water sources and exercise only if temperatures have dropped sufficiently.

Keep your horse safe in hot weather

The most important thing is to be proactive. Don't wait until your horse is visibly struggling before considering how you can help them cool down.

Provide plenty of fresh water, access to shade and good ventilation, adapt exercise and travelling plans, and monitor your horse closely for any changes in behaviour or physical condition.

Summer products such as breathable fly masks and lightweight fly rugs can provide useful additional protection from insects and UV, but they should complement good management rather than replace access to shade, water and appropriate ventilation.

Most importantly, if you think your horse is suffering from heat stress or showing signs of a medical emergency, begin cooling them immediately and contact your vet.

For further advice about horse welfare and caring for horses in hot weather, you can contact HorseWorld's Welfare Team at welfare@horseworld.org.uk or 01275 832067.

This blog post was written by the team of experts at HorseWorld in Bristol. HorseWorld is a horse rescue charity based in the South-West. For more information, please visit our website: