Look at the medical protocol that allowed Damar Hamlin's life to be saved

The NFL requires all teams to have an emergency action plan, for all player facilities, including training camps.

These plans include details about where ambulances are located, the quickest route to the hospital, where medical equipment is stored, and even what radio and hand signals will be used in the event of a medical event.

CNN's Dr. Sanjay Gupta takes a close look at the routine of NFL medical staff.