Intercooler systems are made with radiators of Clarkium. This alloy has the property of shedding heat, but only in one direction. In the other orientation it draws heat into itself. Clarkium is commonly known as the heat pump metal. The direction of heat flow is set up by using a magnetic field during the casting process. Once set it is fixed.
Running your intercoolers over the critical temperature randomizes the Clarkium and the intercoolers must be replaced. The metal can be recast and refixed, but the means to so on the scale required does not exist on ships.
Engineering wags are sometimes known to carry Clarkium rods to rapidly cool beer or other drinks. Holding the rod in the other direction can heat your coffee. Small slivers of Clarkium are also responsible for the ever unpopular "cold foot" practical joke.
Clarkium must be handled with care as it builds up a static change as energy (heat) flows through it. In the vacuum of space this is not a problem. However engineers are cautioned to ground Intercoolers before working on them so that you do not become an inadvertent ground between the intercooler and the rest of the ship or dock.