I am with ross220. I leave the hide on if the temperature is cool enough, though often quarter (leaving the hide on the quarters) a big animal like an elk or moose.
A lot of it has to do with air circulation. Even a medium-size elk can cool down nicely IF it is raised up where the air can circulate around the entire carcass. Twenty years ago I bow-killed a 5-point bull on Sept. 5th, just at sunset. This was on a ranch in central Montana and we could drive a pickup right up to him. After gutting, we drove him back to the ranch headquarters and hung him up on a front-end loader. It got down to 40 or so that night, and he cooled nicely. We skinned him the next day and he was one of the very best elk we've ever eaten.
On the other hand I have also seen the bottom side of a small cow elk start to sour overnight when left in foot-deep snow. The snow acted as an insulator.
One of the guys I hunted elk with in my youth almost always cut the neck off just in front of the shoulders if he had to leave an elk in the woods, whether all day or overnight. Elk are thickest through the shoulders, and cutting the neck off solved any souring problems even in fairly warm weather. He was also careful to get the hindquarters off the ground, but hardly ever skinned any animal in the field. I ate a lot of elk at his house and it was always good.
I have also killed moose at dawn of what promised to be an 80-degree day--and skinned and quartered those immediately. So it depends on the circumstances.
