Surgeon holding a blood test tube https://www.rawpixel.com/image/2287470/free-photo-image-healthcare-workers-blood-test-nurseView licenseFirefighters from the 31st Civil Engineer Squadron rappel down the side of a building during a Rescue Technician One course… https://www.rawpixel.com/image/8727881/photo-image-public-domain-person-manFree Image from public domain license