Is there anything to be concerned about when a kid is hot ALL the time?

He's 10, he's always hot. In the dead of winter he has a fan going and sleeps in a t-shirt and boxers with no blanket. He sweats in long sleeves and dies in a coat. This isn't new, he's always been like this. If it weren't for his age and gender I'd swear he was going through menopause.