What is the first action you should take after positioning the rescue mask on a victim?

After positioning the rescue mask on a victim, sealing the mask is the first critical step to ensure that effective ventilations can be delivered. Sealing the mask creates a proper airtight fit against the victim's face, which is essential for preventing air from escaping and ensuring that the air you provide during ventilations enters the victim’s lungs.

Without sealing the mask correctly, any attempt to provide ventilations may be ineffective, as the air could escape outside the mask rather than entering the airway. This step is crucial, especially in emergency situations where every second counts, and the victim may be in need of immediate respiratory support.

While calling for help, checking for responsiveness, or starting ventilations are important actions in the overall rescue process, prioritizing the sealing of the mask ensures that the next steps in providing care can be effective.