Here are some important numbers and addresses to keep in mind:

Emergency 984-873-0493
Ambulance 984-873-0885, 984-876-2250, 984-879-3154
Police 984-873-4000
Highway Patrol 998-884-1107
Fire 984-879-3670

Immigration 984-873-1884
Office of Tourism 984-873-1001
Public Ministry 984-873-01

Hospitals

Hospiten Playa del Carmen 984-803-1002
Medica del Carmen 984-873-0885
Americano(Cancun) 998-884-6133
Ameri_Med(Cancun) 998-881-3400

Hyperberic Chamber (for dive-related injuries)
Playa del Carmen 984-873-1365
Cancun 998-881-525