First responders are people who are trained to be among the first to arrive at an emergency as well as 911 operators who receive the call and provide assistance or assist in the resolution of emergency situations. They are often employed by the public sector, especially in local government, and may include:
- Law enforcement: Police officers, sheriff's patrol officers, 911 operators, border protection officers, and air marshals
- Fire service: Firefighters, search and rescue members, and technical/heavy rescue members
- Emergency medical services: Emergency medical technicians (EMTs), paramedics, and flight nurses
- Public works: Heavy equipment operators and public works tree department personnel
First responders are critical to response efforts and are expected to be adaptable and culturally competent in unpredictable environments. For example, in a cardiac arrest, first responders may perform CPR, rescue breathing, and use a defibrillator to shock the patient's heart.