The button "a portion of salt" in a gas machine is a remnant of Soviet times. These devices were placed in the production facilities. There was salt water. This is done to restore the salt balance in the body. But not from a hammer (although it also helps from it), but with intense physical activity - sweat is released, it is salty. The salt ends, the sweat is not released, the person overheats and loses consciousness. A slice of such - a spoonful of salt and this effect. On the "Norilsk Nickel"- in the melting workshops still stand.