Anonymous contributor of information about the Cray-1 series (via Tony Cole)

I was one of the field Engineers for Cray-2 Serial Numbers Q1, 2001, 2024, 2101. The heat generated by the Cray-2 is so great that normal air or water cooling is not sufficient. Cray solved this problem by immersing the Cray-2 in 200 gallons of blue, bubbling super-cooled fluorinert.

Fluorinert is clear, tasteless, and inert. Because it can be Oxygenated, it has been used as artificial blood. The Cray-2 was not supercooled. The Fluorinert was cooled by the building chilled water system. The system ran at about 72F. Seymour knew that to make computers faster, wires need to be shortened. Can't be done if there are cold plate, or fins in the way to force the modules further apart. So, to get rid of the cold plates, as used in the Cray-1, he eliminated them, and used direct liquid cooling. Fluorinert is still made by 3M today.