My first postgraduate year after medical school was routine. The second year was not. Seven weeks after induction into the Army, I was sent to Vietnam, issued combat gear, an M-16, and a .45-caliber pistol, and then embedded with 900 infantry troops and 30 medics as the only physician.1 At first I felt like an imposter—a civilian dressed up to look like a soldier—but this feeling evaporated when I began treating wounded troops while under fire, drenched by monsoon rains, or kneeling in a minefield. The learning curve for medical improvisation is steep when there is no suction, oxygen, blood products, or most of the equipment I had previously taken for granted.2 Unlike recent wars where soldiers are meticulous about wearing body armor, we often wore baseball caps and cotton shirts in the tropical heat—one of the reasons there were 57 000 dead soldiers by the war's end.3 When I was hospitalized with severe headaches and fever, I self-diagnosed meningitis, but was relieved to learn it was only dengue fever.