Editor’s Note: This excerpt is from Chapter 7 of Care & Management of Horses by Heather Smith Thomas. 

Most outdoor horses are better off without blankets, but a blanket can help keep a horse comfortable when trailering, during a severe winter storm, or when a horse is sick and having trouble staying warm. A clipped horse will need a blanket in cold weather.

Some synthetic blanket materials are warmer and more weather resistant than wool. Some have lightweight insulating filler material between an inner and outer shell. The outer shell is usually waterproof and windproof. Some synthetic blankets are more durable than cotton or wool and light enough to not press down on the horse’s hair, enabling it to keep its insulating quality.

It can be tricky keeping a horse at the right temperature when using blankets, especially if weather is erratic. If he sweats and gets wet, he may chill later when night temperature drops and he is still wet under the blanket. Don’t blanket him for turnout in the cold early morning and leave the blanket on all day if it gets warm in the afternoon. You might want a heavy blanket for cold nights and a light one for daytime