The Large Hadron Collider (LHC) is one of the coldest places on Earth. The 1.9 K (-271.3 °C) operating temperature of its main magnets is even lower than the 2.7 K (-270.5 °C) of outer space. To get the LHC to this temperature, 120 tons of liquid helium flow around a closed circuit in the veins of the accelerator.
source https://phys.org/news/2020-10-yield-cryogenic-power-large-hadron.html
