# Riding Horses in Hot Weather: A UK Guide
The 2026 heatwave arrived in May. It hadn't finished by June. If you've spent the last few weeks trying to work out when to ride and what to do when your horse is hotter than you're used to, this is what you need to know.
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How hot is too hot?
The number most equine vets use is 28 to 30°C. Below that, most horses in reasonable condition cope well enough. Above it, the risk goes up — and not just because of the air temperature.
Humidity is the part people forget. Horses cool themselves by sweating, and sweat only works when it evaporates. In dry heat, that happens quickly. In humid conditions it barely happens at all, which means the horse keeps sweating, keeps losing electrolytes, and keeps getting hotter. A 30°C day in the south-east during a muggy spell is a different proposition to 30°C in dry continental heat.
The combined measure is called the Temperature-Humidity Index. A THI above 72 means you should be cautious. Above 80, most vets would tell you to stop work. Most weather apps don't display THI directly, but the BHS's rule of thumb is useful: if temperature and humidity added together exceed 100 (say, 28°C at 74% humidity), your horse is working in genuinely challenging conditions.
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When you ride matters more than anything else
Before 9am or after 7pm. That's the usable window in a serious heatwave, and the evening option depends on the forecast — 9pm can still be 26°C in June.
The difference between a 7am ride and an 11am ride isn't just that it's cooler when you set off. The ground is cooler, the air is moving more, recovery is faster, and you're not spending the next two hours managing a horse that can't bring its temperature down. The whole thing is easier.
This means venue choice matters too. If your yard's first lesson slot is 9am and you can't book an earlier arena hire, that venue may not work for you in a heatwave. Somewhere with flexible booking, or a private yard with open early access, gives you options.
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The hosing myth
Almost every rider in the UK has been told not to leave water sitting on a hot horse. You apply it, scrape it off, apply more. It's yard folklore going back decades. It's also wrong.
The science is straightforward. Cold water cools a horse through two mechanisms: conduction — direct heat transfer from skin to water — and then evaporation as the water dries. Scraping removes the water while conduction is still happening and before evaporation has begun. You're undoing the work.
Apply large amounts of cold water and leave it on. Let it run off on its own. Don't rug a hot horse to dry it either — that traps heat rather than releasing it.
Where you apply the water matters. The neck and jugular groove, the large muscle groups of the hindquarters and the girth area cool the blood faster than hosing the legs or back. Start there, work outwards.
Two things to do before you start: if the hose has been lying in direct sun, run it for thirty seconds first — the water inside can be hot enough to scald. And walk the horse down to a working walk for ten minutes before cooling. Don't bring a horse from canter to a cold hose without giving the pace time to come down first.
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Water and electrolytes
A healthy horse at rest drinks somewhere between 25 and 55 litres a day. In a heatwave, or after hard work, that can push past 60. One trough for a field of four horses isn't enough, particularly when the dominant horses drink first and the others wait.
Water needs to be clean, shaded and fresh. Warm water in a green-tinged trough sitting in full sun gets ignored. Change it, scrub the trough, put it somewhere cooler.
Sweat isn't just water loss. It's sodium, potassium, chloride, calcium and magnesium. A horse working in hot weather can lose enough to cause real problems: dullness, slow recovery, reduced gut motility, and in worse cases, tying-up. The early signs are easy to miss — a horse that seems a bit flat, drinks less than you'd expect, takes longer than usual to feel normal after a moderate session.
For a horse in regular work during a heatwave, 25ml of table salt in the daily feed and a salt lick covers the basics. If the work is harder, a commercial electrolyte product is more reliable than a homemade mix, since the balance of minerals matters as well as the quantity. Don't add electrolytes to the drinking water unless you also put out a separate trough of plain water. Some horses won't drink flavoured water at all, and a horse that won't drink is a worse outcome than a horse with no supplement.
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Venue choices in summer
Not all yards handle heat the same way, and it's worth thinking about before you book.
An indoor school gives you shade and drops the effective temperature by a few degrees relative to the outside air. On a 34°C day, a well-ventilated indoor school may be sitting at 29 or 30°C. That's not comfortable, but it's a different conversation to the same work in direct sun, and it extends the usable part of the day past what an exposed outdoor arena can offer.
For hacking, shaded routes make a real difference over anything longer than an hour. Woodland bridleways stay noticeably cooler than open tracks in full sun. If your usual route is mostly exposed, it's worth checking whether the venue or a nearby one has a shaded alternative.
Beach and coastal venues are a genuinely good option in hot weather. Sea breezes keep temperatures several degrees lower than inland, the going is soft, and beach riding almost always stays at walk and slow trot, which means the horse generates far less heat than in arena work. Browse coastal riding experiences on Saddl if you want to get out but want to be sensible about where.
Whatever the venue, check that there's cold hose access near the untacking area before you ride. Finding out the nearest standpipe is a five-minute walk with a sweating horse is not a good discovery to make after the fact.
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Recognising heat stress
A tired horse after a warm ride looks flat and breathes a bit hard. That's normal. Heat stress looks different.
Watch for a breathing rate that stays above 40 breaths per minute ten minutes after you stop work. A heart rate still above 60bpm fifteen minutes post-exercise. Gums that are dry, pale or tacky rather than pink and moist. A horse that was sweating heavily and then suddenly stops. Any wobbliness or distress.
If you see any of those: shade, continuous cold water, and call a vet. Don't wait to see if it improves. Heat exhaustion moves fast and the consequences of doing nothing are severe.
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And look after yourself
It's easy to focus entirely on the horse and forget that helmets and body protectors reduce ventilation and add to your own heat load. Wear the lightest base layer you have. SPF 50 on your face, neck and hands before you get on — not just the nose as an afterthought. Drink half a litre of water before you mount, and have more with you.
If you feel dizzy, stop. That's not a suggestion.