Background: The purpose of this study was to survey the judgments of tourniquet users in simulation to discern opportunities for further study. Methods: The study design constituted two parts: questions posed to four tourniquet users and then their tourniquet use was surveyed in simulated first aid, where the users had to decide how to perform among five different cases. The questions addressed judged confidence, blood volumes, a reason bleeding resumes, regret of preventable death, hemorrhage assessment, need for side-by-side use of tourniquets, shock severity, predicting reliability, and difference in blood losses. The mechanical performance was tested on a manikin. Case 1 had no bleeding. Case 2 had limb-wound bleeding that indicated tourniquet use in first aid. Case 3 was like case 2, except the patient was a child. Case 4 was like case 2, except caregiving was under gunfire. Case 5 was like case 4, but two tourniquets were to be used side by side. Each user made tests of the five cases to constitute a block. Each user had three blocks. Case order was randomized within blocks. The study had 60 tests. Results: In answering questions relevant to first-aid use of limb tourniquets, judgments were in line with previous studies of judgment science, and thus were plausibly applicable. Mechanical performance results on the manikin were as follows: 38 satisfactory, 10 unsatisfactory (a loose tourniquet and nine incorrect tourniquet placements), and 12 not applicable (case 1 needed no mechanical intervention). For cases 1 to 5, satisfactory results were: 100%, 83%, 100%, 75%, and 58%, respectively. For blocks 1 to 3, satisfactory results were 50%, 83%, and 83%, respectively. Conclusion: For tourniquet use in simulated first aid, the results are plausibly applicable because user judgments were coherent with those in previous studies of judgment science. However, the opportunities for further studies were noted.