The absolute first thing to do during an emergency in flight is to listen to and follow the directions of the cabin crew immediately. They are highly trained professionals whose primary job is your safety, and they have the most up-to-date information on the nature of the emergency. If the oxygen masks drop, the first physical action is to put on your own mask before assisting others; this is critical because you can lose consciousness in seconds at high altitudes, rendering you useless to those who need your help. If the emergency is a sudden loss of altitude or severe turbulence, your first action is to fasten your seatbelt as tightly as possible. For a water landing or evacuation, your first task is to leave all carry-on bags behind—even your phone—as every second counts in a cabin exit. By remaining calm and focused on the crew's commands, you significantly increase your own survival chances and the efficiency of the entire evacuation process.