Ah...I so do not miss the sleeping on the sled!?! When the kids were under the age of 3, zipped them up in my coat so they were strapped to me when they fell asleep. Harnesses after that. When my youngest son was under the age of 4, had him in a hiking backpack with my middle kid strapped in front - backpack worked out AWESOME. Them falling asleep was always the biggest issue/problem. The harness works pretty good for that to keep them from bouncing too much... Someone suggested one of those neck brace things they have for kids and dirt biking...which I do have but never used and wish I had. Them sleeping and their heads bouncing around always bothered me?!