Which blanket does my horse need right now?

How horses stay warm

Horses are built for cold far better than we are. Their comfort range, the thermoneutral zone, runs from roughly 41°F to 86°F, well below what people find comfortable. Research on preferred temperature puts their sweet spot near 50°F.

Below the bottom of that range, the lower critical temperature, a horse has to burn extra energy to hold its core temperature. A healthy horse with a full, dry winter coat doesn’t reach that point until about 18°F. A wet, clipped, or summer-coated horse reaches it around 59°F. That 40-degree gap is why coat and wetness matter more than the thermometer alone.

The coat is the blanket

A winter coat works by trapping air. The hair stands up (piloerection) and holds a warm layer against the skin. Anything that flattens the coat or soaks it—rain, sweat, a blanket that’s too heavy—removes that air layer. Snow sitting unmelted on a horse’s back is a good sign: it means heat isn’t escaping.

Hay is the furnace

Fermenting forage in the hindgut produces heat. A common rule of thumb is about 1% more energy for each degree below the lower critical temperature, so on cold nights add hay before you add blankets. Make sure water isn’t frozen; horses drink less in cold weather, which raises colic risk.

What changes the picture

• Wind: breaks up the coat’s air layer. Use wind chill for horses without shelter.
• Rain and sleet: the biggest threat to an unclipped horse. A soaked coat loses most of its insulation.
• Body condition: horses scoring 4 or below on the 1–9 scale have little fat for insulation or fuel.
• Age and health: seniors, hard keepers, foals and horses recovering from illness or surgery run out of reserves sooner.
• Cushing’s (PPID): affected horses often grow a long, curly coat that doesn’t shed and may sweat under blankets. Many do better body clipped and blanketed as a clipped horse.
• Arthritis: cold weather tends to increase stiffness. Keeping these horses warm and moving helps comfort.
• Respiratory conditions: dust and ammonia in a closed-up barn are bigger problems than cold air. Blanket and turn out, or keep the barn ventilated.
• Teeth and hay: digesting forage is a horse’s main heat source. Horses with dental problems or limited hay make less body heat.
• Pregnancy and nursing: late-pregnant and nursing mares already have high energy needs, so cold costs them more.
• Skin conditions: rain rot and scratches thrive on wet skin. Keep these horses dry, but avoid trapping sweat under a heavy blanket.
• Anhidrosis: horses that can’t sweat normally can overheat under a blanket on a warm afternoon.
• Shelter use and barns: some horses won’t use a run-in, and barns with high ceilings or open aisles can stay as cold as outside.
• Individual tendency: some horses simply run warm or cold. Your observations count.
• Acclimation: a horse shipped in from a warm climate may take one to two winters to grow a full coat.

Blanket types

“Blanket” covers a lot of gear. The two words to watch are turnout (waterproof, built for outside) and stable (not waterproof, for stalls only).

Turnout sheet (rain sheet)

Waterproof, breathable shell with no fill. Keeps rain off a natural coat so the hair stays lofted.Use: cold rain, wind, or a clipped horse on mild days.

Turnout blanket

Waterproof shell with polyfill insulation, rated by grams of fill. Sturdy outer fabric for pasture wear.Use: any blanketed horse going outside.

Stable sheet and stable blanket

Softer, lighter-built and not waterproof. Cheaper and more comfortable for stalls.Use: indoors only. Never turn out in a stable blanket when it’s wet.

Liner

A quilted layer (usually 0–300 g) that clips inside or goes under another blanket. Not designed to get wet.Use: building warmth up or down without owning more blankets.

Cooler

Fleece, wool or wicking fabric that pulls moisture away from the skin while the horse dries.Use: after a bath, after work, before trailering. Remove once dry.

Hood or neck cover

Attaches to the blanket and covers the neck. Some come with fill.Use: clipped horses and extreme cold.

Quarter or exercise sheet

Covers the hindquarters while riding.Use: warming up or cooling out a clipped horse in cold weather.

Fly sheet

Light mesh for insects and sun. Not a warmth layer.Use: warm weather.

Weights and fabric

Weight means grams of polyfill insulation inside the shell. Brands don’t agree on exact cutoffs, so check the fill number on the label rather than the word “medium.”

*Adapted from University of Maine Bulletin #1038. Clipped horses step up a weight or two at each temperature; see How this tool decides.

Denier

Denier (D) measures the thickness of the outer fabric thread. A 1200D turnout will stand up to fences and pasture mates far longer than a 600D one. Ripstop weaves stop small tears from spreading. Stall blankets can be lighter denier; turnouts for rough horses should be 1200D or more.

Waterproof vs. water resistant

Only blankets labeled waterproof belong outside in rain. Waterproofing wears off with age and washing; re-proof turnouts each season. Check seams and the area under the surcingles for leaks by feeling the horse after a storm.

Layering

A layering system lets a barn cover almost every night with three or four pieces instead of a closet full of blankets. The rule: the outside layer must be waterproof if the horse goes out, and liners stay dry underneath.

Fill grams in layers don’t add up perfectly—each layer also traps air between them—so treat combinations as approximate and check the horse.

Layering tips

• Add or remove one layer at a time as the day warms or cools rather than leaving the overnight blanket on all day.
• Check that a liner isn’t bunching under the outer blanket at the shoulders or withers.
• In long wet spells, rotate: swap to a dry sheet so the soaked turnout can dry out.

After a bath or workout

1. Scrape off as much water as you can, then towel the legs, belly and the area under the jaw.
2. Put on a wicking cooler (fleece or wool). Keep the horse out of drafts and wind—hand-walk or stall them.
3. If the cooler gets saturated, swap it for a dry one. In cold weather a horse can take an hour or more to dry; a blow dryer or heat lamps in the wash bay help.
4. Check dryness at the skin: part the hair along the back, behind the elbow and on the belly. Damp at the roots means not done.
5. Once the horse is dry to the skin, remove the cooler and put on the blanket the tool recommends.

When the temperature is under about 45°F, consider spot-cleaning, a curry and a hot-towel rub instead of a full bath. If you must bathe, use warm water and plan for the drying time.

Fit and putting it on

Measuring

Measure in inches from the center of the chest, around the point of the shoulder, to the middle of the tail. Brands size differently, so try a blanket on before cutting tags.

Checking fit

• Slide a flat hand under the blanket at the withers and the point of the shoulder. If it’s tight, loosen the chest straps or go up a size.
• Belly straps cross under the belly with about a hand’s width (three or four fingers) of slack—loose enough to be comfortable, not so loose a hind hoof could get caught.
• Leg straps link through each other and hang with some slack.
• The blanket should end near the tail head, not ride forward onto the neck.

Putting it on

1. Tie or hold the horse. Let a nervous horse sniff the blanket first.
2. Fold the blanket, set it gently over the withers, then unfold it toward the tail.
3. Fasten the chest straps first, then the belly straps, then the leg straps. Clip openings face in toward the horse so they can’t catch on hay nets or fencing.
4. Taking it off is the reverse: leg straps, then belly, then chest last. A horse that walks off with only the chest fastened can end up with a blanket around its legs.

Static shocks in dry winter air? Rub the inside of the blanket with a dryer sheet.

Is it the right blanket?

Recommendations are a starting point. The horse is the final word. About 30 minutes after blanketing, and again at night check:

Too warm

• Damp or hot to the touch under the blanket at the withers, shoulder or behind the elbow
• Sweat marks, flattened damp hair, restlessness

A horse that sweats under a blanket in the afternoon may shiver when the sweat cools at night. Go lighter.

Too cold

• Shivering, tucked tail, hunched back
• Standing with the rump to the wind, huddling with other horses, refusing to leave shelter
• Cold skin under the blanket (ears alone are not a reliable test)

Weekly blanket-off check

Blankets hide weight loss and rubs. At least once a week, take the blanket fully off: run your hands over ribs, topline and hips to check body condition, and look at the shoulders, withers and hips for rubs or skin issues.

How this tool decides

The tool builds an “effective temperature” for the horse, then reads it against a coat-specific scale. Thresholds come from University of Maine Bulletin #1038 for full-coated and clipped horses; the short-coat and partial-clip rows sit between them.

Step 1: start with the right temperature

• Open pasture or paddock: wind chill (National Weather Service formula). Also used for horses that won’t use their shelter.
• Pasture with shelter: air temperature, because the horse can get out of the wind
• Stall: air temperature + 5°F, or air temperature alone for a drafty or unheated barn. Barns with high ceilings may be no warmer than outside—use a barn thermometer if you have one.

Step 2: adjust for the horse and the weather

Total adjustment is capped at −30°F. Snow alone doesn’t change the result for a dry, coated horse.

Step 3: read the scale

Above 75°F air temperature, the tool always says no blanket. Any horse on pasture in cold rain (under 55°F) gets at least a waterproof sheet.

These are guidelines, not rules—extension specialists stress there is no single scientific temperature for each blanket. Individual horses differ, and your veterinarian knows your horse.

Research and sources

What the research says

Most blanketing guidance comes from thermoregulation research: the thermoneutral zone, lower critical temperature, and energy cost of cold. One notable study went straight to the horses. Norwegian researchers (Mejdell and colleagues, Applied Animal Behaviour Science, 2016) trained 23 horses to touch symbols meaning “blanket on,” “blanket off,” or “no change.” The horses’ choices tracked the weather: they asked for blankets in cold, wet, windy conditions and asked for them off on warm days. The takeaway many specialists draw is that horses’ needs change with conditions, and blankets should too.

Extension specialists generally agree that healthy, full-coated horses with shelter, hay and water rarely need blankets until temperatures fall into the single digits or below, that wet conditions change everything, and that clipped, thin, old or unwell horses need help much sooner.

Sources

• Winter Blanketing Guide for Equines in Maine, Bulletin #1038University of Maine Cooperative Extension. Temperature scale, blanket weights, fit and fastening.
• To Blanket or Not to Blanket, FS1081Rutgers Cooperative Extension. Critical temperature, energy needs, coolers, wind chill.
• Blanketing Horses: Do’s and Don’ts, ASC-240University of Kentucky Cooperative Extension. Thermoneutral zone of 41–86°F, individual assessment.
• Blanketing guidance from UGA ExtensionUniversity of Georgia. Critical temperatures for winter vs. summer coats; sweating under blankets.
• To Blanket or Not to Blanket (podcast)Extension Horses, Oklahoma State, Rutgers and Minnesota specialists. Blanket if no shelter and below 5°F.
• Transitioning Your Horses from Winter to SpringUConn Extension. Preferred temperature near 50°F; blanketing slows shedding.
• Mejdell, C.M., et al. (2016). Horses can learn to use symbols to communicate their preferences. Applied Animal Behaviour Science.

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