According to the Ford F-250 owner's manual, it is recommended to wear gloves when servicing the vehicle[1]. However, there is no specific mention of letting the engine cool down before opening the hood. It is generally a good practice to let the engine cool down before performing any maintenance work on it, but this may not be necessary for all tasks. It is always a good idea to consult the owner's manual or a specialist if you are unsure about any precautions that need to be taken when working on your vehicle[2][3][4].