That was funny, that's what my mom tells me too...my board bag is a reflective silver color and insulated w/ 5mm of neoprene on the inside, my boards stay amazingly cool in there, I still get too nervous to leave them in the sun tho.
board socks are lame. Get a mylar (reflective silver) board bag.
Even with a mylar bag, always do your best to keep the board cool - shade when possible and never leave it in an unventilated car. Only boards I've ever had blister where colored boards...blue, in fact.