Let’s face it: Space travel is a risky business. Swimming through a void specifically designed to kill any organic life as we understand it is no mean feat, and that’s not even mentioning the various dangers that the political climate can bring to bear. If the vacuum doesn’t boil your character’s blood, the Romulan disruptors pointed at them will. If the hostile natives don’t run a spear through their body, the flesh-consuming bacteria they picked up will finish the job quick enough.
No matter what position and department they fill on a ship or a station, there is always immense risk. But while some of that risk is universal, others are more specialized. A security officer is the first line of defense against enemy incursions. A doctor runs the greatest risk of infection by plagues, due to their exposure to them. Engineers constantly effect repairs in dangerous and less than ideal circumstances. Counselors deal with potentially violent or disturbed patients.