How do you cool the scrotum during the night to make the scrotum hold tightly as it is in the morning? Is there any specific diet?
Diet does not affect your body's temperature. I don't understand why you are concerned about the fact that your body is functioning as it should according to God's design. Your worry is similar to saying you don't want to sweat when you get hot, but your body must do so to keep your temperature within a proper range. To attempt to prevent it would cause the body to malfunction. Attempting to keep your scrotum from expanding to cool your testicles will lead to infertility and a decrease of masculine hormones. Enjoy what God has blessed you with and don't become obsessed with wanting an imaginary ideal.