One player is chosen and they are blindfolded. Another player takes the chosen object and hides it somewhere in the play area. The hider then spins the blindfolded player around. The blindfolded player then must search for the hidden object. They are given directions as to how close they are to the object by everyone else calling out hot cold, they can also indicate if they are getting closer by saying things like hotter/very hot/very cold etc. Once the blindfolded player has found the object, the person who hid it becomes the next blindfolded player.
Source: From the original site.