I have just purchased a Coleman Quickbed Airbed with 4D Built-In Pump.?

Great bed but VERY COLD to sleep on. Had 2 thick quilts and sheet under us to sleep on but it still got too cold after about 2 hours. Has anyone had this problem and if so, have you found some sort of mattress protector/cover that keeps the coldness of the airbed at bay (short of putting an electric blanket on it ... ha ha) ???