It's unfortunate, especially for the victim, but there was a Darwin Award event yesterday afternoon. A big 45' Alfa motorhome pulled into the campground. While hooking up his RV, he decided that he needed more than the 30 amps available at the site. He proceeded to open the service pedestal and attempt to bypass the circuit breakers so he could, presumably, get 50 amp service. Mind you, its rather pleasent here on the coast with high temperatures in the 60's to low 70's. Being a big rig he would need 50 amps to run both his AC units. Since he just arrived, possibly from hotter climates inland, he must have thought he'd need the AC. He has probably done this trick many times before. He won't be doing it again. He electrocuted himself. Fortunately he was traveling alone so he didn't ruin his co-travellers day. He did ruin his neighbors visit. They left the next morning. You really can't be too careful with electricity.
I worked with live electric circuits for more than 30 years, even live underground circuits during rain storms. It can be done, but you can never be casual about it. Among other things, there should be a real good reason to do it. I worked on traffic signals and in an area where there are a lot of ignorant drivers. If you turned them off there would be at least one accident. That seems like a possible good reason. Having an extra air conditioner running doesn't seem that important. If it is, then the next important thing is to do it right. The right shoes, the right gloves, using only one hand, not touching or leaning on anything else. In other words assure you don't and can't become the conductor. There aren't too many second chances.