Doctors and nurses who had to deal with the extremely bright scientists who frustrated them, especially Sheldon.
Monica Garcia as Maria The Status Quo Combustion the nurse that was taking care of Mrs. Wolowitz.
Christopher Neiman as Dr. Dreyfus The Table Polarization who examined Howard for his fitness to return to space.
Phil Abrams as Dr. Bernstein The Engagement Reaction who was the doctor in the emergency room when Mrs. Wolowitz had food poisoning.
Sharon Omi as Nurse The Engagement Reaction who was the nurse who was in the biohazard suit when Sheldon walked into their quarantine unit.
Nurse Althea (Vernee Watson) who showed up in four episodes at a sperm bank, in the emergency room or a floor nurse.