07/01/2026
Recognizing Heat Stress and Other Essential Tips to Help Your Horse Handle the Heat
Heat stress can rapidly become a medical emergency. Horses generate tremendous amounts of heat during exercise, and high temperatures—especially when combined with humidity—can overwhelm their ability to cool themselves through sweating. Severe heat stress can lead to dehydration, electrolyte imbalances, muscle damage, colic, heat stroke, organ failure, and even death. Fortunately, many cases can be prevented with good management.
1. Know the Signs of Heat Stress
Early recognition is critical. Watch for:
* Excessive sweating or an absence of sweating
* Rapid or labored breathing
* An elevated heart rate that remains high after exercise
* Weakness or unsteadiness
* Depression or reduced awareness of surroundings
* Loss of appetite
* Dark or tacky gums
* A re**al temperature above normal that does not decrease with cooling (normal is approximately 99–101.5°F or 37.2–38.6°C)
If you suspect your horse is overheating, contact your veterinarian immediately while beginning aggressive cooling.
2. Cool the Horse Immediately
Current research supports using large amounts of cold water over the entire body as quickly as possible.
Continuously hose the horse with cold water, paying particular attention to the neck, shoulders, chest, back, and hindquarters. Continue cooling until your veterinarian advises otherwise or your horse’s temperature has returned to a safe range.
Using fans while hosing further improves cooling by increasing evaporation. The combination of cold water and airflow cools horses faster than either method alone.
Do not delay cooling while waiting for your veterinarian to arrive.
Myth Busting: Should You Scrape Water Off or Leave It On?
For many years, horse owners were taught to immediately scrape water off after hosing.
Current research shows that continuous application of cold water is the fastest way to reduce body temperature, even if some water remains on the horse.
Effective cooling depends primarily on:
* The temperature of the water
* The amount of water applied
* The surface area covered
* Air movement across the wet skin
If you are applying water continuously, stopping to scrape between applications usually slows the overall cooling process.
If only a limited amount of water is available, scraping before reapplying fresh water can be beneficial because it removes warmed water and allows cooler water to contact the skin.
In other words, when rapid cooling is needed, the priority is to get as much cold water over as much of the horse as possible, as quickly as possible.
3. Encourage Drinking
Provide unlimited access to fresh, clean water at all times.
Cool water is safe for hot horses and encourages drinking. As horses drink, the water replaces fluid losses while also helping absorb and dissipate heat from within the body. Water intake often doubles or even triples during periods of extreme heat, and many horses consume 20 gallons (75 L) or more each day, particularly when working.
Allowing a hot horse to drink cool, clean water is not only safe but encouraged. Restricting water after exercise can worsen dehydration and delay recovery. Most horses naturally regulate how much they drink, and immediate access to fresh water supports both hydration and cooling.
4. Replace Electrolytes
Sweating results in substantial losses of sodium, chloride, potassium, calcium, and magnesium.
A plain white salt block should always be available, but many working horses cannot replace their electrolyte losses from a salt block alone. During hot weather, prolonged exercise, or periods of heavy sweating, a balanced electrolyte supplement is often beneficial. Horses should always have free access to fresh water whenever electrolytes are provided.
5. Maximize Airflow
Good airflow is one of the simplest and most effective ways to help horses stay cool.
Keep barns, stalls, and trailers well ventilated so heat and moisture can escape. When used safely, fans increase air movement across the horse’s body, improving evaporative cooling and helping dissipate excess body heat. Fans are especially effective after hosing with cool water, as the combination cools the body more rapidly than either method alone.
Pastured horses should also have access to areas with good natural airflow whenever possible.
6. Provide Shade
Pastured horses should always have access to natural or artificial shade during hot weather.
Although shade alone will not prevent heat stress, it significantly reduces heat gain from direct sunlight. Remove unnecessary blankets or heavy fly sheets during hot weather whenever practical.
7. Adjust Exercise
Whenever possible, exercise during the coolest parts of the day, usually early morning or late evening.
Reduce workload during periods of high heat and humidity, allow more frequent rest breaks, and monitor recovery carefully. High humidity reduces the effectiveness of sweating, making overheating much more likely.
A horse’s heart rate, respiratory rate, and body temperature should steadily return toward normal during recovery. If they remain elevated despite cooling, contact your veterinarian.
8. Give Extra Attention to At-Risk Horses
Older horses, obese horses, and those with metabolic disease, respiratory disease, cardiovascular disease, or a previous history of heat illness often require additional monitoring during hot weather.
These horses may fatigue more quickly, tolerate heat less effectively, and recover more slowly after exercise.
9. Continue Monitoring After Exercise
A horse continues producing significant body heat even after exercise has ended.
Continue cooling while monitoring heart rate, respiratory rate, attitude, hydration, and body temperature until they have returned toward normal.
10. Be Mindful During Transport
Horse trailers can become significantly hotter than the outside air, particularly when parked or moving slowly.
Ensure excellent ventilation, avoid transporting during the hottest parts of the day whenever possible, and offer water during longer journeys.
https://koperequine.com/understanding-equine-cooling-mechanisms-how-horses-beat-the-heat/
