Horses will start feeling cold below certain critical temperatures. For a clipped horse, or one with a summer coat, the average critical temperature is 40°F. For horses with a thick winter coat, the critical temperature can be as low as 18°F.
In the absence of wind and moisture, horses tolerate temperatures at or slightly below 0° F. If horses have access to a shelter, they can tolerate temperatures as low as -40° F. But horses are most comfortable at temperatures between 18° and 59° F, depending on their hair coat.
Horses are more tolerant of cold weather than heat, but that doesn't mean that they don't feel the effects. When the temperature drops, horses use extra energy to keep warm and, as we have already discussed, they can be at risk of getting sick.
Adequate Shelter
Always remember that horses that are wet or can not get out of the wind are more susceptible to adverse effects of the cold weather, like frostbite. Young horses are even more sensitive and require special care.
Blanketing a horse is necessary to reduce the effects of cold and inclement weather when. There is no shelter available during turnout periods and the temperatures drop below 5 degrees F, or the wind chill is below 5 degrees F.
Horses cope very well in cold temperatures – it is wind and rain that they can struggle with. If you can, provide a windbreak, like a field shelter or even a line of trees, to block some of the wind or rain.
Horses who are cold tend to huddle up in a sheltered place and may not be willing to go out into the pasture area even to eat hay to keep warm. They may really crave their stalls. They may shiver.
HORSES HATE HEAT, HUMIDITY.
Here are some general guidelines: Body Clipped Horses: Start blanketing when the temperature gets below 60° F, or anytime it is rainy or windy. Moderate Hair Coat Horses: Start blanketing when the temperature goes below 40° F. Heavy Hair Coat Horses: Start blanketing when the temperatures go below 30° F.
Another way to keep horses warm is to feed them hay. Heat is produced through the digestion of feed and can be useful in helping a horse maintain body temperature in cold winter weather. The greatest amount of heat is released when microbes in the gut digest high-fiber feeds such as hay.
Turnout sheets are designed for horses to wear for protection from wet weather or mud during cool temperatures. They are usually too warm for horses to wear during hot, summertime temperatures, but they are not insulated with fill so they don't create warmth in cold temperatures.
If you think their winter coat seems thin, stabling at night can help them stay warm. Consider the state of your field too, as it will impact on your horses' health too. If your horse doesn't have access to a shelter in your field, stabling them overnight may be something to consider.
Also keep in mind that horses have thick winter haircoats that provide plenty of protection against the cold. This thick haircoat also tends to be very fluffy and trap air. This layer of air serves as an extra layer of protection in the cold. This layer of air is lost when a horse's coat is laid down flat.
The sound a metal roof can make when heavy rain, hail, tree branches or debris (or worst case scenario lightning) hits it can be deafening and scary, so many horses prefer to stand under large trees during storms or be out in the open.
Forages such as hay require microbial fermentation in the hindgut to maximize their use in the digestive tract. This isn't a completely efficient process, and fermentation results in energy being lost as heat. This heat acts as an internal central heating system, helping keep your horse warm.
Coleman said horses' hair coats can effectively protecting them from cold temperatures, but they stand up less to wind and wet conditions. “If a horse's coat gets wet in rain or snow, it can dramatically chill them,” he said. “You may need to bring them inside a barn to dry and warm up.
Almost every horse benefits from an hour or two of daily human contact, assuming they're spent with a knowledgeable, humane individual. But sometimes, our frontal lobes plan too much for our horses to do.
You can do a quick temperature check of your horse by placing your hand behind the horse's withers. Does it feel cold? If so, then you should consider using a rug / thicker rug. Does it feels damp?
The second colic risk factor associated with winter is exposure to cold temperatures. A horse with a full hair coat should have no trouble staying warm on the coldest of winter days, even without a blanket, as long as he remains dry and has access to shelter.
The temperature you are used to feeling under the blanket is too hot for a healthy horse. Why? Because a horse's body temperature is supposed to be maintained at 38 deg which they can do effectively un-covered but can't with rugs on.
Horses Can't Be Left Alone Due to Potential Injuries and Illness. You can create the safest field or stall around, but if there is a way to get injured, a horse will probably find it. It is very important to check on your horses daily to ensure none of them are suffering from any injuries.
Even a nice walk on the trail will be beneficial. As long as a horse is not shivering, has hay, water, shelter and is in good body condition, outdoor living is perfectly fine.
Horses are mammals and they will inevitably get cold just like the rest of us in harsh winter weather. But you don't need to keep your horse inside all winter; horses are able to withstand colder temperatures thanks to their hardy natures.