FUEL

             This is anything that will burn.  It may be a solid – such as downed timber or kindling.  It may be a flammable liquid such as lighter fluid or kerosene. It may be a gas such as propane.

+

HEAT

           Heat can be generated by friction, focusing the sun, matches or even cigarette lighters.

                                      +

Oxygen

      20% of Earth's air is oxygen.  Fire utilizes the same oxygen as we do.

=

FIRE

         Combine all three elements and you have life saving fire.  Neglect one element and you lose your fire. And you might possibly lose your life.