Helium

Helium is an element added by various mods.

Vanilla
on the Minecraft Wiki

GregTech 4
The Helium Coolant Cell is for cooling nuclear reactors, but it also is required in some crafting recipes. It comes in 3 variations, 60k, 180k and 360k, Each capable of storing the amount of heat it name suggests. Helium Coolant Cells can be cooled down in a Vacuum Freezer.

NuclearCraft
Helium is a common product of due to its very high binding energy per nucleon, but is most easily obtained through the running of. It can be used to produce Liquid Helium.

Liquid Helium is created by supercooling Helium in a. It is used to make and is used by  to cool  in a.