I don't think that's necessarily right. One of the things that's sometimes pointed out here is that it's reasonable for crew to want to not be freezing cold while they're awake. And ironically, many of them spend a lot of time doing very little in the coldest parts of the cabin, ie near the doors. More than once I have woken up in the middle of the night feeling warm, and found the cabin crew sitting on jump seats next to the doors wearing jumpers and swathed in blankets - including men.