I did not notice my stock single case getting very hot, but when I had a 2nd case installed, that's when I noticed. It is probably the case of getting a certain amount of heat from each case with a fixed amount of air flow to cool them. Shove a second case in there with it's added heat and you get higher temps given about the same amount of air flow to cool them. Just like taking a lamp rated for a 60 watt bulb and sticking a 100W bulb in there. What used to be a warm light is now hot to the touch.