One day of environment-induced heat stress damages the murine myocardium

The physiological consequences of environment-induced heat stress (EIHS), caused by prolonged exposure to excess heat and humidity, are largely unknown. The purpose of this investigation was to determine the extent to which EIHS alters cardiac health. We hypothesized that 24 h of EIHS would cause cardiac injury and cellular dysfunction in a murine EIHS model. To test this hypothesis, 7 wk old female mice were housed under thermoneutral (TN) conditions (n=12, 31.2 ± 1.01 °C, 35 ± 0.7% humidity) or EIHS conditions (n=14; 37.6 ± 0.01 °C, 42.0 ± 0.06 % humidity) for 24 h. Environment-induced heat stress increased rectal temperature by 2.1 °C (