I once did agency work for a food canning company, they did a lot of the 'value' tins for supermarket chains- meatballs in tomato sauce, chicken in white sauce, lamb hotpot etc.
I spent my first day unpacking boxes of frozen meat in the cavernous freezer warehouse with no protective gloves so by the end of the day my hands were raw & bleeding.
Second day was spent loading can lids into the machine, again, no protection & once again got covered in vicious little cuts, but that was honestly preferable than having to stare at can lids slowly depleting so you can once again fill it up.
Rinse & repeat for a 12 hour shift, only instead of the arctic it was more like the sweaty himidity of a tropical ranforest with none of its charm.
I noticed there were these weird invertebrates crawling all over the walls, sort of like woodlice, but bigger, leggier & a sort of off-white colour you'd expect to see of some species that had evolved in deep caverns.
My third & 4th mornings were spent power washing the huge carts that moved gallons of slop from one end of the factory to the other, it was mostly welded dried on when we received them & the water pressure had a habit of going up & down, & of course was stone cold.
Oh & these same carts were also used to wheel any waste outside- which looked & smelled like some sort of post apocalyptic wasteland with broken machinery lying about gently rusting away, skips overfilled with stinking meat & the fattest rats I have ever seen scuttling around with no fear of humans.
The afternoons, meanwhile, were spent on 'meat tuck'- standing by the conveyor belt & hand tucking gobbets of raw meat that had missed being squirted directly into the cans, 9 out of 10 cans had one or more of these stringy wee beasties peering out of them so it was all systems go.
I lasted 4 days, went vegetarian & have never eaten tinned food again.