hamstringsally, you don't say what your initial mash temp was. I don't where you are located but I've found the Keep Cool mash tun to be quite reasonable when it comes to maintaining heat. You could try covering the top of the mash (alfoil, camping mat, styrofoam) before putting the lid in place. Maybe even a towel around the join between the lid and the tun. This may help with the temp drop; although I don't know where it started before finishing at 62c.