High Density Server Farms
A new generation of servers is entering data centers with denser racks, making them more susceptible to heat problems. heat has been a constant issue and limiting factor in computing since the beginning. While inroads have been made through redesigned chips and more efficient cooling units, heat is still an issue to be dealt with. Excessive heat raises the prospect of system shutdowns and the consequent loss of service.
Design of data centers is a hot (no pun intended?) issue in systems control. Here's one interesting take on the situation.