The formula is simple: Heat = I²R. Translation: the power wasted as heat equals current squared times resistance. What this means practically is that small increases in current or resistance can lead to explosive growth in heat output. Overheating can shorten the life expectancy of costly electrical components or lead to catastrophic failure. The following are several common cooling methods for distribution boxes: Natural heat dissipation:. In electrical cabinet wiring or industrial automation sites, it's common to encounter situations where terminal blocks overheat severely. In this scenario, the earth distribution block device is very robust.