Since you said his behavior seemed normal, its very possible your layer of substrate protected him from severe damage or you caught it pretty quick. I would just check him for burns, watch him for potential neurological issues <abnormal head wobble, corkscrewing etc> and not panic. Accidents happen and you fixed it pretty quick. 100 degrees or over for prolonged periods could do damage. Maybe put him in a Luke warm soak to rehydrate? I noticed mine like to take an extra drink or 2 when I put them in their soaking tubs.