Horses in training often need their body hair clipped at the onset of winter. The winter coat begins to grow sometime during September (in the Northern Hemisphere) and sufficient time should be allowed for the new hair growth to become established. Your horse can usually be clipped for the first time each year during October. The winter coat continues to grow, but usually not as thickly as the original unclipped coat. One or two additional clips may be necessary during the winter, but the coat should not be clipped after early to mid-January. Any body clipping done later than this can interfere with your horse's spring coat. To reduce or eliminate the need for body clipping consider exposing your horse to light for 16 hours a day. Adding a simple florescent light and timer above his or her stall and setting it to turn on in late afternoon for 6-8 hours beginning in late September or early October, will usually do the trick.
Remember that if you clip your horse in any way a blanket will be necessary on those cold days and certainly at night. When blanketing any horse, clipped or not, never leave blanket on without checking every day. In checking your horses blanket every day you are carefully watching his weight, checking for rub marks that may become open wounds and never allowing him to become to hot or sweaty.
The entire coat is removed. The clipped horse then needs appropriate blanketing.
The hair is left on the legs up to the elbows and thighs, and a saddle pad outline of hair is left on the back. With this clip the legs are protected from cold, mud, cracked heels and injury from briars. The back is also protected from saddle sores and scalding. The clipped horse needs appropriate blanketing.
The lower chest, abdomen, flanks and quarters are clipped as far up as the traces would go on a harness horse. The legs are left covered with hair to the elbow and mid-thigh. Depending on the weather, blanketing may or may not be necessary.
Not clipping is more common than the clipped horse. This makes training and just plain riding a confusing issue and sometimes very uncomfortable for your horse.
When your unclipped horse is sweating after a brisk ride or workout; begin cooling by walking for at least 20 minutes whether inside or outside. If outside and the wind is fierce keep up a slow trot all the way to barn because the chilling wind can stiffen those hot muscles.
When arriving at the barn or your trailer and are out of the wind loosen your girth but leave your saddle in place while you pick out your horses feet and make yourself a bit more comfortable. This gives your horse time to get circulation to return under saddle area.
The next step would be to unsaddle and brush all matted areas of your horse's coat with a curry to separate the hairs helping him dry faster. Towel drying, or blow-drying at this point can be very helpful and speed up the process. As you are working on and around your horse at this time monitor his temperature by putting your hand on his chest (this area will still be damp, like flanks, though the rest of him will be nearly dry), when he feels barely warmer than usual, put on his cooler. Lightweight wool works well for this process. Non -breathable blankets will actually prevent your horse from drying, leaving him cold and miserable.
I like to use wool coolers. Instead of buying wool coolers, you can use wool blankets found at most surplus stores, with clamp as the front closure and a surcingle around his belly, which will also wick moisture. At this time your horse can be fed and watered, keeping in mind to check on your horse in a couple of hours. Only blanket and or turn out if your horse is completely dry.