Horses’ natural furnace is their digestive system. Designed to forage day and night, keeping hay in front of them is one way to keep horses WARM. Here are IMPORTANT factors regarding: choosing hay, its placement, watering, weight management, etc...
Dampness makes for scratches -- Your best defense against crud on heels is to only put bone dry legs in or out. Great grooms never veer from this rule to live by. Here's more on how to treat and protect against scratches...