Liquid gas evaporates worse and worse the colder it gets. Primus 'Winter Gas' improves performance at temperatures as low as -22 °C. After 60 minutes of cooking, a 'Winter Gas' cartridge delivers approximately 9% more power than a conventional cartridge, and 15% more after 120 minutes. The key innovation for Primus Winter Gas is VaporMesh™. The highly absorbent fleece is attached to the inside of the cartridge. It increases pressure in cold temperatures and makes the stove burn better. VaporMesh™ increases the surface area where the liquid gas is converted to the gaseous state. The increased surface area accelerates the conversion process from liquid to gas. The speed of this process determines the pressure in the cartridge. Therefore, compared to conventional cartridges, Winter Gas works without problems even in conditions where cooking with gas was hardly possible before.