Very good point stockshowkid’97 on the differences for clipped and unclipped horses.
Personally I’ve found this combination very effective in the cold winter nights.
Rambo with medium fill
Turn out sheet on top
*under 20 then heavy rambo over medium and under T/O sheet
*under 20 then Medium rambo over blanket
This combination really locks in the heat but still breaths enough to keep them from sweating.
I think it is also wise to consider how warm the barn becomes when all the doors/windows are locked up tight at night. (it can really heat up in there if you have 20+ horses in the barn) Furthermore, if your horses get additional hay at night check this will keep them warm as well (chewing and digesting).
During the day there are a lot of factors to consider (wind, moisture, open windows/doors, sun shinning in the windows/sky lights, number of horses in the barn making heat, did this one just work (ride, treadmill, lunge?) ect. Clipped or unclipped.. how thick is the unclipped hair. Does he look like a bear or did the heating lamps keep the coat from growing in full?
What works for me…
I find sliding my ungloved hand on the horses shoulder can help me determine to take a layer off or add one.
To prevent blanket rubs we constantly reset blankets and pull them forward (beware it may get you a bit in the a$$ by a sensitive few). Temperature changes so much throughout a day. Its really important to go through the barn adjusting, pulling off or adding layers multiple times a day.
OCD Blanket Checking & Adjusting Confession:
First thing in the AM
Before and after turnout
One hour after riding
Night check – usually done my other, but they text me the temp inside the barn and send a picture of the horse’s layers of blankets.
Hope this helps