Solid carbon dioxide. Instead of melting, it sublimes at −78°C (195 K) at standard pressure. It is used as a refrigerant or cooling agent. It is also used in the preservation of foods such as ice cream and has the advantage that it leaves no residue after sublimation. It is also used in fog machines to produce dramatic fog effects, and in plumbing to freeze water to form a plug in a pipe to allow repairs to be made. It is also used to remove warts by freezing the infected skin, and is also used to attract biting mosquitoes and midges. Dry ice is produced by either carbon dioxide capture or manufacture from another process such as fermentation, and pressurized or refrigerated until it liquefies. When the pressure is reduced causing some of the carbon dioxide to vaporize, there is a lowering of the temperature of the liquid resulting in solidification. The solid carbon dioxide is then compressed into blocks or pellets.