The problem with sheets-only is that it mats down their fur, so they lose their natural insulation. That's why people buy medium-weight blankets with some fill. That fill replaces the insulation their fur would normally give them, plus tops it off with a waterproof layer to prevent them getting wet & shivery. If you don't want to spring for another waterproof piece of horse clothing, just get a mid-weight stable blanket that you can layer underneath a waterproof sheet. Amigo makes a nice stable blanket and then you can just hook up 1 tail strap to both sets of D rings. Easy peasy.
"You become responsible, forever, for what you have tamed." - The Little Prince
This happened to me on Christmas actually! I thought a storm was going to come in later Christmas day and it actually came over night and I did not put a blanket on my horse. I got out there early Christmas day and she was wet so I towel dried her. I was worried about putting a blanket on her bc I didn't want it to make her colder. I put on the medium weight and came back a few hours later after it had gotten below freezing and she was completely dry under her blanket and warm. I was so happy that it worked out okay!
It was simply foul yesterday. Mine were sheeted and never got wet but I switched them to their mediums before nightfall/after the rain stopped. I think it might have been a freakish thing with the rain/cold/wet as mine were also cool to the touch under their sheets. Had been eating hay all day.
"Kindness is free" ~ Eurofoal
--- The CoTH CYA - please consult w/your veterinarian under any and all circumstances.
My wooly mustang mare got soaked somehow and she was miserable. I've never seen her cold even when she had a layer of ice on her back. I think she must have rolled because it wasn't raining that hard, but she was wet to the skin. I didn't have a stall at the time, but I brought her into the barn and gave her some mash. I put a sheet on her and stuffed a bunch of hay under it. She shook for almost half an hour until she finally started to dry off. When it's cold and they get really wet they definitely aren't happy.
Wool also has this property (keeps warm when wet). Cotton does not- and I don't like to use a cotton irish knit or other cotton cooler in the winter if wetness is an issue.
I have a couple of wool coolers, which I love for keeping the horses' backs and haunches warm while tacking up, doing walk warm-up, and after untacking on cold days (the horses are body clipped). But I do not keep them on wet or steamy horses for very long in cold weather, because once they have pulled the moisture from the horse, they can actually make a horse feel chilled (wool tends to hold moisture - esp. if used under a sheet that isn't particularly breathable). Wool can also be pretty heavy, esp. when wet.
So, for the above reasons, I am planning to pick up a couple of fleece coolers. Fleece is lighter in weight then wool, very breathable and absorbent, it has great wicking abilities and insulates well even when wet. And it dries much faster than wool, so it can be left longer on a damp horse without worrying about chilling the horse.
Rainsheets, lightweight turnouts, whatever you want to call a waterproof sheet with no insulation don't have enough squash factor on a healthy horse's natural coat to make him colder. Unless you've managed to find some ancient ton weight piece of crap, or are using something with a high friction lining that is trying to crawl off over the horse's tail and pulling very tightly on the rest of the horse (which is something that shouldn't be used on the horse in the first place).
Horses can fluff their coats under midweight blankets - rainsheets are not a problem. The wind and wet resistance granted by a rainsheet more than makes up for the minimal squash effect on the horse's coat. I have run pasture kept horses through weeks of -31F highs with a rainsheet on without having any issues. I see a rainsheet as a personal, portable shelter for a horse - his own wind and wet protection wherever he is. I see fluffed coats to various degrees when I take off a rainsheet, depending on the external temperature, the weather and the horse. I was surprised to find horses can fluff their coats under midweight blankets because I too used to buy into the "blankets squash haircoats" myth. In my experience the squash factor starts to become an issue when the blanket gets into the 300gm and up weight.
New to me this year is a horse who seems to be slightly chillier than most horses, so I have gone with an uninsulated neck rug to block a bit more wind and wet rather than increasing the blanket weight from 200gm. It's worked really well for him and he still has the fluff ability to control his own temperature to some extent.
For anyone who thinks they see a contradiction in this info - the rainsheet through the -31F high is for unclipped horses. I use the midweights on my partially clipped working horses. They live out all the time so I need them to be able to have the ability to fluff their coats at night to increase their insulation factor, and in turn flatten their coats if the day is warm. The 200gm turnouts allow them to do that.
If my horses are wet and cold, I either bring them in to dry, or throw more hay out. I don't like to blanket a wet horse.
Getting them out of the rain, and giving them a bunch of hay warms them up pretty quickly!!
I've done both...blanketed when wet and towel dried before leaving for the night. Today it was almost 70 degrees and then by the time I got home one of my horses was shivering as it had started to rain hard and had been raining for some time apparently. I toweled him and put a blanket on him for a bit when he came in but he still shivered... took the blanket off and toweled him some more and he was fine...took about a half hour but he was definitely getting warmer.
Shivering in horses is a voluntary thing, that they do while a little chilled to keep warm/warm themselves back up. Think of it more as their vibrating internal heater.
So are horses the only animals that have this unique ability? I certainly cannot elect to turn off my "internal heater" when I'm shivering nor can my dog or cat if they get wet.
OP. I live in an area where it doesn't snow but the COTH consensus seems to be that snow is much easier since it sits on top of a fluffed coat and actually acts as insulation. I think nearly any horse will get cold standing in the rain for an extended period of time in the winter. Heck, my sister's robust morganX shivers at 65 in the rain. Clearly no one told her that she is supposed to be impervious to rain. On a sunny day she would be fine into the 30s without any blanketing but the minute it starts raining she needs something to deflect the rain or she gets uncomfortable very quickly.
For a cold wet horse I bring them into a stall ASAP. I purchased thermal cotton weave blankets from walmart..very cheap...for this purpose. I use the cotton thermal blanket alone or under a wool cooler after I towel them as much as possible. I just change the thermal blanket as it soaks up the water. They get toasty under the wool cooler/ thermal blanket very quickly.
I bought the thermal blankets for about 10 dollars each. I got the idea after I purchased a very expensive wool cooler with a cotton knit liner. It worked really well but it was heavy and hard to wash.
I live about 1.5 hours north of LA and I put rainsheets with a little insulation on both my horses unless we are in a warm spell high 60's-70's in the day 50's at night. I get the Big D rainsheets that have some insulation but not much. Both horses hate being wet and the blankets last several years and are about $80.00.
Both horses are in outside paddocks with a metal roof over the feed area. So winds will certainly get them chilled.
I'm not a blanketer, but shivering horses is not acceptable IMO. Like the OP, just once in all my horse-keeping years have I had a horse shiver, and like the OP, it was on a cold but not freezing day, and I put a blanket on him as soon as I could!
I asked on this board once about blanketing a wet horse as it was raining here, temp was dropping fast and far, and my horse was standing outside in the rain (his choice.) (It wasn't that cold when he stood in the rain.)
The advice was to tie him in the barn for an hour with a flake of hay so that he would dry, and then blanket him. That worked fine.
I've had to put sheets on wet horses. Not sopping wet, but more than damp. They dried out fine, because modern sheets are breathable. At 40 degrees and rainy, I would just use a sheet with no fill. I'm in California, so it's rarely any colder than that and raining. Any time it's really cold, it's dry (it doesn't snow where I live).
I no longer believe that a sheet flattens their hair and makes them cold. I sometimes leave the sheet on in between storms, and they are always warm underneath the sheet. There's really no way to know if their hair is flat because the sheet is flattening it, or if it's flat because they are warm under the sheets. But they always feels warm underneath.
This. I don't buy the "Blankets flatten their coats and make them colder"
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