Personally, I think a bee sting hurts more, but scorpions creep me out. One experience I've had with the sting of the bark scorpion was when, as a newbie to the desert years ago, I left my polarfleece jacket resting on the ground as I sat with friends around the evening campfire. Only later upon donning my jacket did I feel the painful jab in my arm from a little bark scorpion intent on teaching me a lesson in desert etiquette. My field treatment, after the bout of initial swearing, was to place a bandanna soaked in cool water on the sting and take some Ibuprofen. I did have a "pins and needles" kind of tingling in my arm for the next few days. This is due to the neurotoxic venom.
Scorpions sting with their tail and the general rule is the smaller the pincers the more toxic the venom, so watch out for the little guys. The bark scorpion (Centroides) is the one that most people get stung by in the Southwest, particularly in the Grand Canyon. What's a bummer for us is that the bark scorpion is the only one out of the more than 40 types of scorpions in the Southwest that are active hunters and can climb on walls. Most scorpions reside in their subterranean hideout waiting for prey (other insects) to happen along, and then they pounce. The bark scorpion, however, roams the landscape in search of prey. Did I mention they also like hikers' sweaty boots to hole up in after hours, or other garments (and sleeping bags) left unattended at night?
While writing my book on desert survival, I spoke with the research staff at the University of Arizona toxicology department in Tucson to get the latest treatment methods. Basically, most people who are stung by a scorpion use ice on the sting site and take Ibuprofen if needed. Something like 90% of stings occur in the home and at night (on that nocturnal trip to the bathroom), not in the wilderness. If symptoms are severe or kids are involved (smaller body mass to absorb the toxin), then a call to poison control or the ER was recommended.
I had a friend who was stung in his bed in Sedona, Arizona. He received two stings on the spine while rolling over and another on his thumb while trying to swat the creature. Within thirty minutes, he had violent muscle-spasms in his legs and was becoming incoherent. His wife called 911, and the paramedics took him to a nearby hospital whose ER doctor happened to have lived on the Apache reservation and had seen his share of stings. His treatment was to administer vallium to control the spasms and monitor my friend, who ended up being discharged the next morning. He later told me that he had received countless scorpion stings in his 25 years as a river guide on the Colorado but nothing as uncontrollable as this bout. He was wiped out for a week due to the physical exertion from the spasms and had the tingling sensation for another week.
You can avoid a lot of problems with most desert creepy crawlies by choosing a campsite away from rockpiles, fallen trees, and other debris. Perhaps due to the damp, micro-climate it creates, scorpions love to rest under a fresh cowpie, so clear these away from your site! And when you are staying at a friend's house or in a fancy hotel in the desert, remember the golden rule--don't put your hands or feet where you can't see and check your bed!