What protection is needed to access the crawlspace under the house?
Unfortunately I have to work in crawl spaces a lot.  I don a cheap Tyvek jump suit/coveralls with a hood over my regular clothes. You can find them in the paint dept of Lowe's or HD for about $20.  I also wear boots, mechanics gloves and some safety glasses.  There are always some bugs, spiders, and I've met a woodchuck or two. Take a good flashlight and check ahead of you carefully to avoid any unpleasant encounters.  At least we don't have poisonous snakes in Maine!!!!!!   OMG!!!!!       Good Luck.