Last updated: November 5, 2026
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At the Fair Grounds on Louisiana Derby Day, my grandson noticed some horses wearing blankets and others without. “Why?” he asked. You might have wondered the same thing after seeing a horse wearing a sheet in July—or when deciding whether your own horse needs one.
Here’s how to tell those coverings apart, whether a rain sheet keeps a horse warm, and how to know when a blanket does more harm than good.
Table of Contents
Why Do Horses Wear Blankets?
A healthy horse with a full winter coat handles cold better than many people expect. His coat traps insulating air, and digesting hay helps him produce heat from the inside, according to the LSU AgCenter. A blanket helps when his coat isn’t enough to keep him warm, especially if he’s thin or exposed to wind and rain.
The LSU AgCenter lists the horses most likely to need one in extreme cold. Those include horses that may get wet, horses with a poor coat or that are clipped for showing, and very young or very old horses. Thin or unhealthy horses, horses that aren’t used to the cold, and horses with no shelter from wind and weather are on the list, too.
That’s how I manage my horses, not a temperature rule for every horse. A clipped, thin, or wet horse may need a blanket at much warmer temperatures. For guidelines by coat and clip, see this guide on when to blanket a horse.
Why Do Horses Wear Blankets in the Summer?
When you see a horse covered in the middle of summer, it’s usually wearing a fly sheet, not a winter blanket. A fly sheet is lightweight mesh that lets air through while reducing insect bites. Some also offer UV protection to help reduce sunburn on vulnerable skin and limit coat bleaching. Check the sheet’s UV rating rather than assuming every mesh sheet offers the same protection.
Not every horse needs one. A horse that’s bothered by flies, or one with pink skin that’s prone to sunburn, may be more comfortable in a fly sheet with good UV protection. A horse without those problems may do fine without it. And a fly sheet can still make a horse too hot in hot, humid weather, so check underneath for sweat.
You’ll also see lightweight sheets on show horses to keep a freshly groomed horse clean before he goes in the ring. After exercise, you may see an anti-sweat sheet or cooler used while a horse dries, which is a different job from fly protection. This guide to horse cooling sheets covers when to use them.
Do Rain Sheets Keep Horses Warm?
A rain sheet can help a horse stay warm by keeping his coat dry, but it adds little insulation of its own. A waterproof turnout sheet usually has no insulating fill. Its main job is to keep rain off the coat, which loses insulating value when it gets wet or muddy.
That doesn’t mean every horse needs one when it rains. His coat, condition, shelter, and the temperature all matter, according to Rutgers. If he needs extra warmth as well as rain protection, a waterproof turnout blanket with fill does both jobs.
Horse Blankets vs. Sheets: The Main Types
A blanket has fill for warmth. A sheet has little or none. Turnout versions are designed for outdoor use, and stable versions generally aren’t waterproof. For wet-weather turnout, choose one labeled waterproof.
Turnout blanket. Waterproof, breathable, and filled, for a horse turned out in cold weather. More fill generally means more insulation.
Stable blanket. Filled like a comforter for a horse kept in a stall, but generally not waterproof.
Turnout or rain sheet. Waterproof with little or no fill. It keeps off rain and wind but doesn’t add much warmth.
Stable sheet. A light cotton or nylon sheet that keeps a horse clean indoors, often after grooming or before a show.
Fly sheet. Lightweight mesh that reduces insect bites. Some also offer UV protection.
Cooler. Usually fleece or wool, it wicks moisture off a sweaty horse so he can dry without getting chilled.
You’ll also see quarter sheets on cold-weather rides, and show scrims and dress sheets at shows and on race day. For fill weights, measuring, and fit, see this horse blanket guide.
When a Blanket Does More Harm Than Good
More covering isn’t automatically better. A few things to watch for, according to Rutgers and the LSU AgCenter:
Sweating. If he’s sweating underneath, he’s too warm. Take the blanket off or use a lighter one, depending on the conditions.
Blanketing a wet horse. Don’t cover a wet or sweaty horse with a waterproof blanket. It can trap moisture against his skin and leave him chilled. Let him dry first, using a fleece or wool cooler to wick away moisture if needed.
A flattened coat. Wearing a blanket continuously can flatten the winter coat and reduce some of its natural insulating ability.
Hidden problems. Don’t put a blanket on and forget about it. Check underneath for sweat, rubs, and dampness, take it off regularly to look at his skin and body condition, and make sure it still fits.
The right answer depends on the horse, his coat, and where he lives. A blanket should fill the gap his coat can’t, not replace it.
About Miles Henry
Racehorse Owner & Author | 30+ Years in Thoroughbred Racing
Miles Henry (legal name: William Bradley) is a professional horseman based in Folsom, Louisiana. He holds Louisiana Racing License #67012 and has spent over three decades managing Thoroughbreds at premier tracks including Fair Grounds, Delta Downs, and Evangeline Downs.
Expertise & Hands-On Experience: Beyond the track, Miles has decades of experience in specialized equine care, covering everything from hoof health and nutrition to training protocols for Quarter Horses, Friesians, and Paints. Every guide on Horse Racing Sense is rooted in this “boots-on-the-ground” perspective.
30 of their last 90 starts
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