Stress.
I get a lot of tourists in my area trying to casually summit the local 14,000ft mountain in sandals. Some weeks in the summer are absolutely nuts for SAR and the emergency room staff.
Revealing personal information about yourself on the internet.
Compressed air. I was once putting air in a car tire while on a road trip with a friend. After filling the last tire I handed him the tube and started screwing on the cap. For some dumb fucking reason, he thought it would be funny to stick the air tube in my ear and turn it on.
I couldn’t hear out of that ear for like 20 minutes and it hurt so fucking much. I probably should have gone to the hospital but the pain went away almost instantly and my hearing came back so I just didn’t fucking go.
Trampolines. Especially with multiple people.
Long hair around pulleys and belts.
There’s a YouTube channel where two young ladies are working around a sawmill with long hair, and I can’t count how many times people have begged them in the comments to tuck their hair up. They don’t.
Water on the road. You might be able to drive through it, but more often than not you shouldn’t try to.
Wild animals
I was in Thailand when a 30 year old got bitten by a monkey. Her complaint? No one had warned her not to pet the monkeys. Honest to God.
The bison living in Yellowstone.
Riding a horse is comparable with serious extreme sports, and head injuries are the most common.
Motorcycles, atv’s, really anything without a cage around it. Even if you wear a helmet, the brunt of the impact force goes on your spinal column.
Blunt kitchen knives. One might think, oh this is just a flat piece of steel but cutting becomes tearing and crushing. The extra force this takes can easily send the knife off in an unintended direction in a swift and uncontrollable manner. Then you find out what a flat piece of steel can do to your fingers.
Sun burns would be treated much differently if they were called by their true name, radiation burns.
Those bullshit carny rides at state fairs.
Resin! It is toxic if not used with appropriate ventilation and equipment (including gloves and a mask) but everyone uses it for projects in their little apartment studios. Always stresses me out to see that.