I've always wrapped my receivers in foam. The Airtronics radios don't have heat issues like Futaba does, and maybe JR/Spektrum. IMHO you're better off wrapping it in foam if you have "wet" power in the plane. The vibrations can do a lot to a circuit board. You could probably just put foam underneath the receiver and then secure it in place. I just prefer to wrap it in foam.

Ken