he worst humidity I've ever been in was in Missouri in August many years ago - but I don't think it was anywhere close to what you're talking about!
Nah, that's probably about the same as we get here. I took a trip with the Boy Scouts to Philmont Scout Ranch in NM several years ago at the end of July. Miserable here, and pretty much exactly the same in Memphis and Chicago. Got to NM, got off the train and thought, wow this is nice! Of course it was actually hotter and few days later I forgot to sunscreen my ears (doh!) and literally had blisters.
So yeah, we're pretty muggy, but at least we're not in danger of spontaneous combustion or anything. Your 118 sounds a bit worse to me.
And to bring us back on topic, I solved the "cool my shop" problem by putting a small heat pump in. It's a split unit, like a typical home would have, but the indoor part is completely self contained and hangs on the wall (no duct work, etc). My shop is a detached garage, so I can't exactly mooch off the house (well, I guess I could have ran a duct across the driveway, but I don't think the wife would have appreciated that. 
)
-j