Heat...what everyone need to know

Ok my fiancé and I own a hottub. We would go in it a few times a week, when we went to start trying for baby, the doctor told us that the heat from the hottub kills all sperms. Just one time in hottub. She goes on telling us about a couple that has been trying for a very long time and they couldn't have their second baby. The sperm count came back very very low. Well to come to find out the husband got a new truck and it has heated seats and he was killing all his sperm everyday! After turning off heat they got pregnant that next month. Just some things you don't think of. Baby luck ladies:)