For the first time, the Yorkshire Ambulance Service has granted access to its Hazardous Area Response Team (HART), one of 15 specialist medical units set up after the 7/7 London bombings to treat badly injured patients in extreme environments.999: NHS Rescue Squad's unprecedented access will show viewers the camaraderie and courage of men and women who risk their lives to save ours and the blood, sweat and tears required for the physically demanding and thorough training regime, testing skills ranging from nuclear decontamination to using high-speed flood relief boats.