Heat kills drives so avoiding it is a big plus. I've had friends buy neat looking cases that didn't have proper drive cooling and the hard disk died. At three separate employers we had weekend air conditioning failures and each time hard drives died not just over the weekend but the following weeks as well.
My machines are in 4U server cases with a dust filter on the front, a 120mm fan in front blowing on the drive cage, and two 80mm fans in back pulling air through. Temps in the case stay low.
The other key is quality power supplies. A poor p/s can kill your drives or the motherboard with that on-board "RAID" functionality.
Make backups and take steps to avoid hard drive abuse through heat or unstable power. That should be good enough