I wouldn't overlook summer as an opportunity to beef up your application.
@jqueb29 Maybe this is a regional thing because I literally don't know anyone who didn't work or research or do something (mostly full time or multiple part time positions) over summer.
Also, I was a summer camp counselor and would highly caution against trying to study for the MCAT as a counselor. It will depend on your camp, but most camp jobs are basically 24/7 with an hour break a day, a night off, and less than 24 hours without kids at camp, which you will not want to/be able to spend studying. Consider internet access, time getting to/from your study space, and the fact that you will likely want to spend every waking moment you can with your bff camp counselor friends.
That said, if you can swing studying for the MCAT some other time, camp is so awesome and I would definitely do it again personally.