I HATE leaving them overnight, but sometimes it is the best plan. I've done it twice, once on of my deer, once a hunting partners. On his, we found the arrow, got about 8 inches of pentration, we tracked a bit into a THICK swamp, and jumped the deer. We backed out immediately. Figuring a 1 lung hit. At this point it had been about 30 minutes since the shot. Found it the next morning about 200 yds above the swamp, looked like we busted it out, it ran up into the hardwoods and bedded down, we found it there in the AM. If we had pushed along the previous night the deer would have kept moving. There was little to no blood and we probably would have lost it.

Mine, was a gut shot, arrow looked completely clean but was covered with clear slime. I watched the deer run around 150 yds, we found no blood, pass through arrow. Hunting partner thought he heard it crash, but we decided it was just busting through a wall of brush. We backed out came back in the AM. After about 1 hour of searching, still no blood, we found the doe lieing almost completely under water is an ice cold stream! Nicely chilled all the way through!! My hands got cold gutting her.

When you leave them overnight, if they die and lay for a decent amount of time, the ground actually can work like insulation and the meat that is lieing along the ground will probably spoil first.

Personally unless I am convinced the deer isn't dead yet, I am going to stay after it, unless I loose the trail.