I bought a horse in November. Since I've had him he's been in a lightweight rug pretty much all the time. He feels warm, and is a good weight. He is clipped, but just a bit off his neck/chest. Just about every other horse at the yard where he is kept seem to be in medium/heavyweight rugs when the temperature drops below about 5 degrees and I am starting to doubt myself. I'd be interested to know what rugs people on here are using when it gets chilly. Thanks.