I'm from Missouri and have had on more than one occasion chiggers so bad that I couldn't sleep. Once I made the mistake of laying down in tall grass while waiting for my ride home from camp. BAD IDEA! There wasn't an inch of my body missing the notorious bumps chiggers leave behind.

The best prevention really does seem to be taking a warm shower immediately after getting home. I haven't had the ring of fire since I started taking showers after hiking and fishing through tall grass.

If you're unlucky enough to have the ring of fire, a hot oatmeal bath really seems to help (something like Aveeno). When you get chiggers really bad, it's the only thing that seems to cover everything well enough.