I've noticed that after a few minutes use, the connector/head begins to get a bit warm. I picked up after a couple hours, I check the temp, it was at 25 degrees Celsius, when I felt it getting warmer I stopped and checked the temp. It was at 32c. I always set it down for a bit when it warms irregardless, but is this something I need to watch out for? What temp should I set as an alarm?