Try not to run the machine when tired.
A few years ago I helped my father move his business and the accumulated junk from 25 years in the same location. Took me 8 full weekends with the help of many others. I used the tractor by attaching the bucket forks and a pallet and loading the pallet, and transfering the items to box trailers. I filled seven 53' trailers.
One night, my exhausted help had left and I was determined to finish loading the trailer we had worked on all day. The pallet got loaded heavy for each trip. My last trip, I had lifted the pallet up, but could not rest it in the trailer like before. I jumped out of the machine and trudged to the trailer, completely oblivous that the macine was slowly skidding away (in 2wd, idling with p-brake on, no counter weight, no loaded tires and minus my big butt). I caught it, but I realized after that I took a big chance running to catch it and jumping in. When that much weight is on the pivoting front axle and very little weight is on the rear, coupled with the load raised to 5 feet or so, this was a roll-over waiting to happen! All this and it was rolling/sliding backwards downhill and on a slight crown of the road! Of couse I ran along side it on the down hill side of the crown. I lucked out, but honestly can't explain why. Looking at it now, I should have been squashed.
When your tired and your main goal is to be done as soon as possible, your judgement is poor. The more you're tired,the worse your judgement can be. Add some heavy equipment, and thats a painful mix.