On the nature of the link between malignant hyperthermia and exertional heatstroke.

Malignant hyperthermia (MH) is a rare myopathy inducing severe accident when carriers are exposed to triggering agents. MH susceptibility (MHS) is assessed by pharmacological tests performed on muscle strips. Exertional heat stroke (EHS) is a severe accident occurring during long and strenuous exercise. It has been observed that numerous EHS patients are susceptible to MH according to pharmacological tests. Because most of those EHS-MHS subjects were soldiers, we hypothesize that military duty could select subjects with infraclinical myopathy and therefore would increase the MHS:EHS subject ratio.