When Is It Too Hot To Ride Your Horse?

Start With Temperature Plus Humidity

• As a general rule, you can gauge whether it’s too hot to ride by adding the actual temperature to the percentage of relative humidity. For a 90-degree day with 85 percent humidity, the total is 175, not to mention a wild, frizzy hair day.

• Here’s where things get muddy. What is the magic number? It depends. I found numerous articles on this topic, each with a different magic number. It might be 140, 150, 180, or above. Generally speaking, the hotter and more humid the weather becomes, the more cautious you should be.

• Humid weather can raise a horse’s temperature because the water in the air prevents effective evaporation of sweat. When searching for the ideal temperature, consider the humidity more than the temperature.

• The National Weather Service also issues warnings about extreme heat and high humidity, so check your weather apps. Look for high heat index values and take heed.

Not a huge fan of this nonsense. Time to skip riding.

The FEI has a Different Way to Measure Things

• Sometimes, the “temp + humidity” trick will steer you wrong. The FEI began measuring the “hotness” in 1+986 as it prepared for the Olympics in Atlanta. They use a gauge to measure temperature, humidity, solar radiation, and wind. Here’s what the indicator does: 

“The WBGT Index The only validated heat index for equestrian sport is the WBGT index3 . This was developed primarily for management of the three-day event cross-country at the Atlanta 1996 Olympic Games but was also used in Athens 2004 and Beijing 2008. An FEI project to refine the guidelines based on the WBGT for Eventing, Dressage and Jumping is currently in progress. The WBGT index is a single “temperature” that takes into account the effects of air temperature, humidity, sun and wind all at the same time. It is calculated from a measurement of Wet Bulb temperature and a measurement of the temperature inside a black globe (Figure 1). Alternatively, it can be measured with an inexpensive (~US$160; £120; €140) handheld device such as the ExTech HT30 which is widely available (Figure 2). The WBGT index = 0.7 x Wet Bulb Temperature (°C) + 0.3 x Black Globe Temperature (°C) Why do we use the WBGT Index? The WBGT Index is used because although it’s only one number, it accurately weighs up all the factors that determine thermal environmental load. It is also easy to measure with simple and inexpensive equipment such as the ExTech HT30 “

• Do we have access to this gauge? Usually not, so we need to use common sense and look at the big picture to keep our horses out of the danger zone.

To read the entire Olympic sweat studies from the FEI, download this.

Other Factors Indicating It’s Too Hot to Ride Your Horse

Your horse’s fitness level

• The high-performance sport horse ridden six days a week at top levels can usually cope with heat much easier than the weekend warrior horse that is sedentary all week and then worked on the weekends.

• A horse’s fitness level can be measured and tracked over time using vital signs. This includes your horse’s temperature, heart rate, and respiratory rate. You can measure vital signs before you ride, during the middle of your ride, and immediately after the exercise. Then, take vital signs every five minutes until your horse’s vitals return to normal.

• As a horse gains fitness from month to month, their vital signs during exercise will lower, and their recovery rate will shorten. Your horse will also be better equipped to work for more minutes of moderate-intensity exercise.

The intensity of your horse’s exercise

• If you notice your horse having a harder time in hot conditions, back off the physical exertion.

• You may be able to modify your horse’s exercise in hot, humid conditions. There is no need to gallop cross country. How about a trail ride instead? If you’re lucky, you might find a creek and enjoy the cool water splashing around.

• Shorten the duration of your ride. Tack traps heat.

Your horse’s health conditions

• A younger horse with a clean bill of health will cool down more easily than a horse with health problems. This is especially true for horses with heaves or allergies, which interfere with breathing. Although there is not a significant amount of heat loss due to respiration, some heat is lost. Heaves and some allergies create stress on the respiratory system, impeding heat loss.

• Also, note that rapid breathing can worsen in unfit and unhealthy horses.

A foamy horse does not mean they’re overworked or overheated. It means the latherin protein in the sweat was rubbed, creating foam.

Your horse’s sweating patterns

• In the case of anhidrosis, there’s a direct line between the lack of sweating and overheating. Anhidrosis occurs when sweating doesn’t occur at all or when a horse sweats in smaller amounts. This is particularly dangerous in hot and humid weather, as the horse can’t cool down with sweat. There is a high risk of heat stress and overheating.

• On the other hand, excessive sweating can also be a problem. That blasted humidity traps moisture on the skin, and your horse may respond by sweating more. Horse sweat is unique because it’s a fluid, but it’s also chock-full of salt and other electrolytes. Excessive sweating can lead to dehydration and disrupt your horse’s vital mineral levels. Humidity makes everything worse.

• Thanks to some brilliant horse-stuff manufacturers, you can get cooling blankets for your horse. Perfect for cooling down after a ride. 

• If you notice that your horse has stopped sweating, this is a significant indication of heat stroke, a dangerous condition that requires immediate veterinary care.

Is your horse dehydrated?

• Check their vital signs. Monitor your horse’s temperature, pulse, respirations, and even digital pulses as you are grooming your horse. Above-normal vital signs, especially an elevated body temperature, indicate that the body is already working hard to overcome the combination of heat and humidity. It’s always a good idea to check in with your vet, just in case.

• To monitor hydration levels, check their gums. They should feel slippery, not sticky or dry. Anything other than slick is a sign of dehydration.

• You may notice that his gums have changed colors; that’s also a sign that things can go sideways in the horse’s body. Gum color gives clues to your horse’s circulatory health. Pale pink gums are the norm; any other color, like hot pink, purple, red, or even shades approaching blue, is a sign to call your vet.

• Continue to check their vital signs, especially your horse’s body temperature, as you ride and cool out.

• It’s always too hot to ride while dehydrated.

Your horse’s weight

• Extra weight interferes with the body’s ability to regulate vital signs. That additional, fatty insulation traps heat and may help bring a horse’s temperature to dangerous levels.

• Overweight horses may also tax their cardiovascular systems more. Read more about the overweight horse here.

Your farm’s amenities

• Are you riding outside in the blazing sun, or is the arena well-ventilated and covered? Are there shaded round pens or paddocks that your horse could exercise in instead of the sun?

• Sure, you have a hose and a cross tie for a cold water shower after a workout, but is it shaded? Or do you have access to a ventilated area with shade?

• What about fans? While cool water is helpful when your horse is hot, adding a fan enhances the evaporative cooling effect. Their body will thank you when they can chill in some breezy shade.

This is my horse’s normal sweat pattern for a hot-ish day.

The time of day

• I love to start my day early so I can ride before the ultra hot weather hits. The early mornings tend to have cooler temperatures, and if you’re lucky, the bugs will still be asleep. Twilight or late evening is also a great time. Beat the heat by going early or late! High noon is asking for trouble.

• Also, pay attention to the sun. Direct sunlight may be more stressful for your horse’s body temperature, but cloud cover can lead to high humidity levels.

• Weather conditions can change rapidly, often accompanied by a lot of hot air, so pay attention to the forecasts. You may get lucky, and a storm will blow out some of the hot temperatures!

How long has your horse been in a hot climate?

• Acclimation to temperatures and humidity levels takes time. Ho,t humid weather isn’t the norm for all horses. If you live in Canada and travel to Florida for the winter, you will leave the icy cold and arrive in a sauna.

• Don’t forget about sudden weather changes brought by weirdly hot days. There is nothing wrong with taking a few days off from riding and exercising to get through the heatwave.

How are your horse’s diet and drinking habits?

• If you even suspect your horse will be sweating, feed electrolytes beforehand. For all-day sweating and non-stop heat, refresh those electrolytes in the afternoon, too.

• Because dehydration is a possibility, encourage your horse to drink as much as possible. Ideally, you already know what your horse likes mixed with their water. You can add apple or fruit juice, a tablespoon of his favorite feed, or even a sports drink. Always offer flavored water alongside unflavored water in case your horse is feeling picky.

• Add water to your horse’s meals. Soak the hay for a few minutes and turn the feed meals into a more mushy consistency.

Is Your Horse Overheated (Hyperthermia)?

• The surefire way to know if your horse is overheated is to take his temperature. Now, you may come back from riding, and their temperature is above normal. They need to trend back down towards his normal body temp. Check every five minutes.

Other signs of overheating include:

• Gum discoloration
• Abnormal vital signs
• Sweat that is sticky and thick
• A previously sweating horse stops sweating
• Acting depressed and lethargic

Call the vet. Don’t wait, don’t check the internet, don’t grab lunch, call the vet.

For the love of all things horse, use a thermometer for your guy.

What to do if Your Horse is Getting Overheated

• Do not feed electrolytes. Their body is already unbalanced, and electrolytes can exacerbate the issue. Electrolytes should be administered before exercise or when your horse is expected to sweat.

• Do not force any water into his mouth. If they want to drink, they can. Provide fresh water.

• Do not give any medications.

• Your vet can give you exact instructions to follow. This may include dousing with water and using fans. Some treatments can make matters worse, so rely on your vet’s plan. Play it safe when in doubt, and consult your veterinarian to determine what is best for your horse. 

• Do monitor your horse’s body temperature. A simple thermometer measuring rectal temperature and a notepad can help you track your horse’s progress.

The most practical tip for deciding if it’s too hot to ride

When in doubt, don’t ride. There are endless things to engage your horse, and sometimes the hot weather demands that high temperatures = a day off.

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