Firefighters work under extremely dangerous conditions, risking their own lives to save others as they battle fires. Called “first responders,” they are usually the first emergency personnel at traffic accidents or explosions and may be called upon to put out fires or treat injuries. Once at a fire, they use axes to break down walls or windows so they can evacuate people trapped by flames and other obstacles. Rescue squads take first-aid equipment to fires and help the injured until ambulances arrive. They also may be called for injuries and accidents not caused by fire, such as heart attacks. Despite the dangers, firefighters take satisfaction from providing an important public service.