Simple logic and the ability to pull yourself back. Constant phrases like: "This is a third-year disease. Not an inflammation of the left pancreatic heel" or a similar disease I made up. A little logic and self-control, gentlemen.
Fortunately, for all the time I was studying in medicine, I never had a desire to try certain diseases on myself. Rather, even on the contrary: you listen to everything, and then in the subway you fearfully grab the handrails, alcohol gel for hands is always with you.