I'm on a four-day course this week to become a qualified First Aider for work. As a biologist, I've got a reasonable grasp of how the human body works and the kinds of things that can go wrong, and as my Mum was1 a nurse, I've absorbed a lot of very sensible information from her about first aid, so I'm not finding anything too difficult so far. We've spent quite a lot of time today either pretending to be unconscious2, or pretending to treat people who are pretending to be unconscious. Actually, it's quite a lot of fun.
On the way back from the course, I was suddenly much more aware of all the people around me, and all the myriad ways in which they could have accidents or their bodies could suddenly pack up. It's ridiculous, but I was thinking, "Please, no-one have a heart attack or a stroke today, because we don't get to those kinds of things until Wednesday. Simple loss of consciousness, minor cuts, bruises or burns would be acceptable."
2 In other words, pretty much my normal Monday work state. ↑