One thing to be very, very careful of with permethrin-treated clothing is that it's very water-soluble, and extremely toxic to fish. If you go swimming while wearing permethrin-treated clothing, you will leave a trail of death in your wake, and not just of the bugs you were hoping to kill...
I feel compelled to note that it's also quite toxic to cats (but not dogs). This is one reason you should never use flea products intended for dogs on your cat.
