Chlorine gas has a relatively high critical temperature of 382.5 K (109.4 °C). This means that it is relatively easy to liquefy chlorine gas by simply cooling it below its critical temperature. However, the boiling point of liquid chlorine is -34.04 °C, so it is also very easy to vaporize liquid chlorine by simply heating it above its boiling point.

Therefore, in order to keep chlorine liquefied, it must be stored at a temperature below its boiling point but above its critical temperature. This is why chlorine is typically stored in pressurized tanks at a temperature of around 25 °C.