We evaluated empirically the extent to which the use of a cognitive aid during a high-fidelity simulation of a malignant hyperthermia (MH) event facilitated the correct and prompt treatment of MH. We reviewed the management of 48 simulated adult MH scenarios; 24 involving CA 1 and 24 involving CA 2 residents. In the CA 1 group, 19 of the 24 teams (79%) used a cognitive aid, but only 8 of the 19 teams used it frequently or extensively. In the CA 2 group, 18 of the 23 teams (78%) used a cognitive aid but only 6 of them used it frequently or extensively. The frequency of cognitive aid use correlated significantly with the MH treatment score for the CA 1 group (Spearman r = 0.59, P < 0.01) and CA 2 group (Spearman r = 0.68, P < 0.001). The teams that performed the best in treating MH used a cognitive aid extensively throughout the simulation. Although the effect was less pronounced in the more experienced CA 2 cohort, there was still a strong correlation between performance and cognitive aid use. We were able to show a strong correlation between the use of a cognitive aid and the correct treatment of MH.