Seymour Cray used to say this all the way back in the 1970s: his biggest problems were associated with dissipating heat. For the Cray 2 he took an even more dramatic approach: "The Cray-2's unusual cooling scheme immersed dense stacks of circuit boards in a special non-conductive liquid called Fluorinert™" (https://www.computerhistory.org/revolution/supercomputers/10...)