Just because we feel the cold doesnt mean that our horses do. When temperatures go below 0C, horses who arent rugged will require more food to keep warm because theyll start to use more energy, but they still dont necessarily need to wear a rug.One of the major sources of heat for horses is the fermentation of fibre and forage a bit like the old Readybrek advert for kids, forage is central heating for horses. Most horses will cope well without rugs as long as they have ad-lib forage available.What is thermoregulation?Horses and humans have different reactions to the cold and we need to keep this in mind when rugging.The horse has the same mechanism for keeping warm or cooling down that humans have.When we get too hot, the blood vessels in our skin start to open up and that increases the amount of heat that is lost at the surface. As we get colder, those blood vessels narrow and less blood goes to the skin.In many ways, thermoregulation in both horse and human is the same. When we get too hot, we start to sweat or we may increase our breathing rate we see that in horses and in people. When we get too cold, we reduce our blood flow to the surface even more and may start to shiver and its much the same for horses.The thermoneutral zoneA persons temperature alters constantly, and its the same with horses. This fluctuation is how we keep our temperature within our thermoneutral zone.This is the range of temperatures within which youre not obviously trying to keep yourself warm or cool yourself down, so youre not shivering or sweating. Within both the human and horse thermoneutral zone, body temperature is controlled through the blood flow to the skin.The differences are the extent to which these are used and the capacity for cooling and heating.One key difference is the size of a human compared to a horse. Large animals are good at keeping heat in and small ones are better at losing heat. In cold weather, a big horse, for example, will feel much more comfortable than a small bird. Thats why many birds migrate in winter.The horse is interesting and different in that it can survive in climates from minus 40C to plus 40C.The horse is very well adapted, even though its a large animal. Technically, horses should be better off in cold temperatures because of their size, but they do well in the heat because they have an incredible capacity to sweat.No other animal can sweat more than a horse. If we compare the rates of sweating through the same amount of skin, a cm of horse skin can sweat three to four times as much as cm of human skin.So providing that sweat can evaporate, horses have three to four times the capacity to cool themselves through sweating than we do, even though they are five to six times bigger.When do horses feel cold?For humans, our thermoneutral zone (when we dont have any clothes on) is between 25C and 30C. Without clothing, once it gets below 25C, we feel cold.A horse with a natural coat has a thermoneutral zone of between 5C and 25C.What this means is that the horse is able to tolerate a much greater range of temperatures before they need to do anything to keep themselves warm. A horse generally doesnt start to feel cold until its 5C or lower.As autumn comes and we reach for our fleeces at around 10-15C, our horse doesnt perceive that temperature drop in the same way, so were not doing our horse any favours by piling on the rugs.They simply dont need them, as theyre already wearing the equivalent of a four-tog duvet. Of course, if your horse is fully clipped, then they will start to feel the cold sooner, just as we would.We tend to over-rug because we think that since were starting to feel cold, our horses must be too, but thats a big misconception.Some horses do need a rugHaving said this, some horses will benefit from being rugged. Influencing factors include:ClippingClipping a horse that is in work means they will dry quicker after theyve sweated during exercise. However, a fit horse whos clipped and in work will need rugging to replace the protection their natural coat would give them in very cold weather.Even if theyre stabled at night, theyll require at least a mediumweight rug with a neck cover to prevent too much heat loss.Breed and typeBreed and type play a part too. A Shetland pony with a thick coat is less likely to need a rug than a fine-coated Thoroughbred, for example.A cob or native breed who is overweight but otherwise healthy, and has a full coat, doesnt need a rug until temperatures reach 0C overnight or until it gets very wet and windy and the horse is living out with no shelter.Otherwise, ad-lib forage and shelter are adequate.Low body condition scoreSimilarly, horses that have a low body condition score, are ill or recovering from injury or illness, have respiratory, heart or lung disease or chronic illness, as well as older horses and very young horses, should all be rugged when the temperature drops.The parallels are similar in humans older people, very young children and babies, and people with chronic illnesses need help staying warm. Just as with horses though, there are individual variations: some people walk around in t-shirts and shorts while others are wearing woolly jumpers.Poor doersHot-blooded horses such as Thoroughbreds often feel the cold more than a warm- or cold-blooded horse, and will require rugging to maintain their weight, especially if they are prone to losing condition in the colder months.A horse who loses weight through the winter would likely need a heavier rug to give a higher level of protection.Veteran/poorly horseAn older or recovering horse with any of the following would benefit from being rugged sooner rather than later:Low body condition scoreNeed to gain weightHas a reduced appetiteIsnt eating huge amounts of forageHas some issues with teethHas a predisposition to colicHas other health issues such as compromised liver functionRug overnight with a medium-weight rug and possibly rug them during the day too. If they live out, ad-lib forage and shelter are vital.Weather conditionsThe weather can also have a big impact on whether to rug a horse or not. When you have a combination of rain, wind and cold, horses may benefit from a lightweight, waterproof sheet because they lose considerably more heat if theyre wet.If its 10C and dry, thats very different to 10C and wet and windy.The availability of shelter is an important consideration too. If a horse has ample shelter so they can get out of the wind and rain, theyre less likely to need a rug.Dr David Marlins members area on his website provides access to science-backed information spanning a wide range of horse-related matters, including webinars, latest research findings, independent product trials and celebrity interviews, with the additional opportunity to join a friendly, supportive private community of fellow horse lovers. Pay-monthly membership is 8. Find out more and join here.Related contentDoes your horse really need to wear a rug or blanket?How important is it for a horse to wear a rug when it rains?How to use Mother Nature to help your horse lost weight before spring and why its good for themUltimate guide to horse health insurance and vet fees coverThe post When do horses feel cold? Dr David Marlin explains appeared first on Your Horse.