The sports world was sent into a state of shock as Buffalo Bills safety Damar Hamlin suffered commotio cordis during a Monday Night Football game against the Cincinnati Bengals. In football, injuries are far from uncommon, but the severity of Hamlin’s condition required medical attention beyond the on-site capabilities of team trainers and sideline personnel. That is where the NFL’s emergency action plan comes into play.

Each of the league’s 32 teams is required to create one to deal with extreme situations like what happened to Hamlin, according to the NFL. As part of the plan, all clubs must identify a nearby level one trauma center, and have both an ambulance and airway management physician at the stadium during game days. These plans are then reviewed by the NFL and the NFL Players Association, before receiving required approval from a third-party expert.

After that, all teams must practice their emergency action plan at least twice prior to the start of the season. According to The Athletic, these practices consist of numerous drills that deal with a variety of different potential injury scenarios, including spine or head trauma, isolated head trauma, heat illness, cardiac arrest and trauma to the abdomen or lower body.

Additionally, the league staffs every game played with an average of 30 healthcare providers, including two EMT crews to operate advanced life-support ambulances. Per the NFL Player Health & Safety guidelines, officials meet with these healthcare workers, along with team medical staff, one hour before kickoff to run through the logistics of all emergency situations. The NFL’s officiating crews are also responsible for ensuring that ambulances, defibrillators and other necessary medical equipment are on hand.

“The paramedics, the emergency-response team, I thought that they were on it. They were composed,” Bengals head coach Zac Taylor said after Monday’s game.  “It was obviously a complicated situation on the field that everybody was trying to process, and for me personally, being down there and seeing the composure that everybody involved had, obviously not knowing how the situation was going to unfold, I was led to believe it was going to be positive because of how they handled it. And I think that’s important to point out that they were prepared, and they gave Damar the best chance.”

Once a game is underway, all emergency response personnel are connected via a headset or walkie-talkie and utilize hand signals to indicate the level of care needed for an injured player. During a conference call following Hamlin’s injury, NFL Executive Vice President of Football Operations Troy Vincent told media members that the league reviews these procedures with each of its teams on a weekly basis.

Coordinated emergency responses are planned and rehearsed with the hope that they will never have to be called upon. However, their existence can make a critical difference for someone in a life-threatening situation.