When I'm feeling exhausted or run down, I will never [again] do anything in a kitchen that involves equipment more dangerous, fragile, or complex than a spoon.
When I first went off to university, I got a job working at a diner. Originally I was supposed to wait tables, but after half a day of serving families whose children had apparently been raised by wolves, and which left religious tracts as tips (yes, really), I asked the manager whether I mightn't fill the currently vacant position of bus
boykid. The manager agreed reluctantly (it meant paying me minimum wage, instead of two dollars an hour), and said the position was mine, if no one else came along.
The diner was a busy one, and that afternoon I didn't once stop clearing tables, or loading and unloading the dishwasher until nearly 23.00. Have I mentioned that this wasn't an exciting job? Also, I didn't want too look like a baby or a whiner, so I didn't ask for a break at any point, and after an hour or so, I was running on autopilot, my mind far, far away.
As a result, I brought my first day to a dramatic close when, near midnight, I went into the back, opened the dishwasher, and began unloading it, starting with a full tray of glasses, which I set down on the top of the machine. The problem was that while I was out front bussing, someone had dumped a large heap of plastic spoons onto the top of the unit. I saw the spoons, realized the problem, but was still in Stepford bus-kid mode, and, with my brain saying 'OHnononononononoooo...' somewhere off in the distance, I precisely placed the tray on the heap of spoons, stepped back, and watched the whole thing crash to the floor in an avalanche of smashing glass and bouncing spoons. To make things worse, I reflexively dropped to the floor in a crouch, and brought my hand down on a spike of glass.
The racket brought a rush of staff to the back, and they found me still crouching on the floor, surrounded by broken glass, plastic spoons, and arterial spray, too tired to be upset, or even think of anything more than 'Huh, that's a cut artery, it's squirting rhythmically.'
The lesson about not doing things in the kitchen when fatigued was reinforced (I tend to need reinforcement, evidently) some years later, when I was way too tired to tie back my long hair, but was good to bake bread. Using a mixer... Ouch.