What should be done first according to the P.A.S.S method when using a fire extinguisher?

The first step in the P.A.S.S. method for using a fire extinguisher is to pull the pin. This action is essential because the pin serves to prevent accidental discharge of the extinguisher. By pulling the pin, you release the locking mechanism, allowing you to operate the extinguisher effectively. Once the pin is removed, you can then proceed to aim, squeeze, and sweep as instructed in the method. Each subsequent action relies on the proper execution of the first step, making it critical to remember in emergency situations. This structured approach ensures safety and effectiveness when combating a fire.