If there are two people at the scene of a fire, ideally one should work the fire extinguisher while the other calls 911. We definitely need to practice this at home, said Millie Reyes, 40. To use a fire extinguisher correctly, experts say that one should remember the acronym P.A.S.S. --. P: Pull the pin. A: Aim at the base of the fire. S: Squeeze the trigger. S: Sweep side to side. But they say the most important lesson of all is when not to try using an extinguisher.