Some time ago I was using a milk crate as a stool to get up onto my bench. On getting down, it slid out from under my foot and I landed flat on my back. Normally I bounce but this time I bounced my head and knocked the wind out of me. Stayed down for a minute or two. Repurposed the crate and went to the store for a 2 step stool with rubber feet. It works great. Added an inch of Armaflex insulation to the top and it also makes a great seat for low work.