... How mean is the sting of those critters? ...
Hurts like heck, according to my girlfriend who was stung on the hand by one crawling under her pillow.
Incredibly painful, light headed, metalic taste in your mouth, lasts 2-3-4 hours, then it's just a puncture wound (infection possibility etc) according to the experts. Bark scorpion is the most deadly but even then only like 2 people died from it in the last few decades. Mostly if they're allergic, I think. Bark scorpions are the only ones that can crawl up vertical walls. Comforting to know that they might be on your ceiling while you sleep. They like to come inside in the fall.
If I had to rank what I'd like to get bit/stung by in the desert, I think I'd pick (least problems to most problems) -
1) Gila Monster (bites but no long lasting toxic problems, but you have to physically pull him off of you)
2) Scorpion (toxic but no local tissue damage)
3) Black Widow (local tissue necrosis seems typical and lots of bites are on the hand, just where I don't want to lose mobility)
4) Rattlesnake (local gross tissue necrosis, maybe nerve damage, muscle atrophy etc, perhaps most expensive treatment. Anti-venom is $25,000 per injection, you typically require ten injections. That's not a typo)
5) Human (probably hardest to shake off. That whole vampire problem to deal with)
I've come face to face with them all and so far have been able to avoid their sting/bite...
Sgt Lumpy