When temperatures soar, horse owners face a unique and serious challenge: keeping our horses safe, comfortable, and healthy in extreme heat. Unlike us, horses cannot simply remove layers or retreat to air-conditioned spaces, and their large body mass means they can struggle to dissipate heat effectively. Heat waves can quickly turn from uncomfortable to dangerous, leading to dehydration, heat stress, and even life-threatening conditions such as heatstroke.

One of the most important things to understand—yet often overlooked—is that horses need time to acclimatise to heat. Sudden spikes in temperature are far more dangerous than consistently warm weather because the horse’s body hasn’t yet adapted. In this article, we’ll explore how heat affects horses, how to manage them safely during a heat wave, and the practical steps you can take to minimise risk.

Understanding How Heat Affects Horses

Horses regulate their body temperature primarily through sweating. As sweat evaporates, it cools the skin—similar to how humans cool down. However, this system has limits.

In high humidity, sweat doesn’t evaporate as effectively, reducing the horse’s ability to cool itself. On very hot days, especially when combined with humidity, a horse can quickly become overheated even at rest.

Signs that a horse is struggling with heat include:

• Excessive sweating or, conversely, lack of sweating
• Rapid breathing or flared nostrils
• Elevated heart rate
• Lethargy or reluctance to move
• Dehydration (sunken eyes, slow skin pinch test)
• In severe cases, collapse

Understanding these signs early is critical—heat-related conditions can escalate quickly.

The Importance of Acclimatisation

Horses do not instantly adapt to hot weather. It typically takes 10 to 21 days for a horse to acclimatise to increased temperatures. During this period, their body gradually becomes more efficient at cooling itself. This includes:

• Producing sweat more effectively
• Conserving electrolytes
• Improving circulation to dissipate heat

A sudden heat wave—especially in places like the UK where temperatures can spike unexpectedly—means horses are often caught unprepared. This is why the first few days of hot weather are the most dangerous.

Key takeaway: Reduce workload and increase monitoring during the first phase of a heat wave, even if your horse is usually fit and healthy.

Hydration: The Cornerstone of Heat Management

Water is the single most important factor in managing a horse during hot weather.

A horse can drink anywhere between 25–55 litres per day in normal conditions—and significantly more during a heat wave. Dehydration can occur rapidly and has serious consequences.

Tips to Encourage Drinking:

• Provide constant access to fresh, clean water
• Check water sources multiple times daily
• Offer water in both stable and field
• Add a small amount of apple juice or electrolytes to make water more appealing (if needed)
• Ensure buckets and troughs are not too warm—horses prefer cool water

Some horses are fussy drinkers, particularly when away at competitions. Training them to accept flavoured water in advance can be a useful strategy.

Electrolytes: Replacing What’s Lost

When horses sweat, they don’t just lose water—they lose essential salts (electrolytes), including sodium, potassium, and chloride. Without these, muscles and bodily systems cannot function properly.

Signs your horse may need electrolyte support:

• Heavy sweating
• Reduced performance
• Sluggish recovery after exercise

Electrolytes can be provided through:

• Commercial electrolyte supplements
• Salt licks (though these are often insufficient alone)
• Adding salt to feed (under guidance)

Always ensure fresh water is available when feeding electrolytes—never give them to a dehydrated horse without water access.

Shade and Shelter: Essential, Not Optional

Access to shade is critical during a heat wave. Horses left in direct sunlight for prolonged periods are at much higher risk of overheating.

Ideal Shade Options:

• Natural shade from trees
• Field shelters
• Open barns or shaded yards

If natural shade is limited, consider adjusting turnout times to avoid the hottest parts of the day.

Turnout Management in Hot Weather

Turnout routines often need to change during a heat wave.

Best Practice:

• Turn out overnight when temperatures are cooler
• Stable during the day if facilities are well-ventilated
• Avoid peak heat hours (typically 11am–4pm)

However, stabling is only beneficial if the stable is actually cooler than outside. Poorly ventilated stables can become dangerously hot.

Stable Management: Keeping Air Flowing

A hot, stuffy stable can be worse than being outside. Air movement is key.

Tips for Cooler Stables:

• Maximise ventilation (open doors, windows)
• Use stable fans where safe and appropriate
• Avoid overcrowding
• Keep bedding clean and dry

Rubber matting with minimal bedding can help reduce heat retention.

Exercise: Adjusting Workload Safely

During a heat wave, exercise should be carefully managed.

Guidelines:

• Ride early morning or late evening
• Reduce intensity and duration
• Allow frequent breaks
• Monitor recovery time closely

Even fit horses can struggle in extreme heat, particularly if they are not acclimatised.

A horse that normally recovers quickly but remains elevated in heart rate or respiration after light work is a warning sign

Cooling Your Horse Effectively

Cooling techniques can make a significant difference—but they must be done correctly.

Best Cooling Methods:

• Hose with cold water, focusing on large muscle groups (neck, shoulders, hindquarters)
• Scrape excess water off and repeat
• Continue until breathing and temperature return to normal

There’s an old myth about not using cold water on hot horses—this is outdated. Cold water is one of the most effective cooling methods when used properly.

Feeding Adjustments During Heat Waves

Digesting food generates internal heat, so diet plays a role in heat management.

Feeding Tips:

• Provide forage during cooler parts of the day
• Avoid feeding large meals during peak heat
• Ensure forage is fresh and not dusty or mouldy
• Consider soaked feeds (e.g., soaked hay or beet pulp) to increase water intake

Hydration can be supported through feed as well as water

Travel and Competitions in Hot Weather

Travelling horses during a heat wave adds another layer of risk.

Key Considerations:

• Travel during cooler hours
• Ensure good ventilation in the horsebox
• Offer water frequently
• Allow rest stops on long journeys

At competitions:

• Prioritise your horse’s welfare over performance
• Withdraw if conditions become unsafe
• Use shade, cooling, and hydration strategies aggressively

Recognising and Responding to Heatstroke

Heatstroke is a medical emergency.

Symptoms:

• Very high body temperature (above 40°C)
• Rapid, distressed breathing
• Weakness or collapse
• Confusion or unresponsiveness

Immediate Action:

• Call a vet immediately
• Begin aggressive cooling (cold water, shade, airflow)
• Do not delay treatment

Quick action can save a horse’s life.

Special Considerations for Vulnerable Horses

Some horses are more at risk in hot weather:

• Older horses
• Overweight horses
• Horses with thick coats or underlying health conditions
• Horses not used to heat (lack of acclimatisation)

These horses need extra monitoring and more conservative management.

Planning Ahead: Be Proactive, Not Reactive

Heat waves are becoming more frequent, so preparation is key.

Your Heat Wave Checklist:

• Reliable water supply
• Electrolytes on hand
• Adequate shade
• Cooling equipment (hoses, scrapers)
• Adjusted turnout plan
• Emergency vet contact readily available

Being prepared reduces stress—for both you and your horse.

Final Thoughts

Managing a horse in a heat wave is about awareness, preparation, and adaptation. The biggest mistake horse owners make is underestimating how quickly heat can impact their horse—especially when temperatures rise suddenly and horses haven’t had time to acclimatise.

By understanding how horses cope with heat, recognising early warning signs, and making practical adjustments to management, you can keep your horse safe, comfortable, and healthy—even during the hottest days.

At the heart of it all is a simple principle: listen to your horse. They will always give you signals—your job is to notice them and respond early.

Because when it comes to heat, prevention isn’t just better than cure—it can be lifesaving.