Why are deer on their feet in the middle of the day in the middle of the summer? I've noticed this for years now but have never really heard a plausible answer.
Their hair fibers are hollow and act as air conditioning of sorts. Plus they get much of their water intake via greens, so eating is kinda like getting a drink.
My assumption has always been that it's simply because they need to eat and as someone else said, they get the vast majority of their water from the browse they consume.