A cooler is a wool or fleece covering for your horse that allows heat to dissipate without making your horse cold. Both of these materials have wicking properties that remove the moisture from your horse’s coat, allowing it to dry.
If your horse is very sweaty and you have two coolers available, swap them out when you see moisture bead up on the one covering your horse. Moisture on the outside of the cooler means it is too damp to wick away any more sweat.
Additionally, if you have an Irish knit sheet, it can be helpful to place this on the horse first, under the cooler. The holes in the knit will create a layer of warm air to help dry his coat, while the cooler will wick away and absorb the moisture.
There are a few additional ways you can dry your horse as rapidly as possible.
Thatching. Place fluffed up hay or straw under the cooler and directly against his skin. The hay or straw will capture the horse’s naturally dissipating heat and create warmth to dry the damp hair more quickly.
Toweling. Rub off the sweaty areas in vigorous circles will also help, as will using a cloth dampened with rubbing alcohol.
Baby powder or corn starch will also absorb sweat without the drying effect that rubbing alcohol can sometimes have.
Once your horse’s coat is dry, you can safely turn him out or put him back in his stall. It’s especially important that he be dry if you’ll be putting on a turnout blanket, as these will trap moisture, keeping his coat wet and potentially causing discomfort.