All animals when dead start decomposing at the moment of death. And gutting the animal, and washing it out does Not cause bacteria to grow. Bacteria starts to grow as the temperture starts rising, At 40 degrees or below the bacteria will be stalled, or slowed down from growing. Even a slaughter house will wash out an animal then hang it to age the meat. We've been hanging and washing out our deer for the 42 years I've been hunting, and longer than that with my Dad, Uncles, and Grandfather. Here in Michigan come November when the deer season is on, it normally doesn't go above 45 to 50 degrees, And if it does then the deer should be put into a cooler. If you're worried about food poisoning, that is caused by improper handling of the meat, and temperature. With proper handling and cooking, all bacteria will be killed off, and the meat will be fit to eat.