The purpose of this study was to examine the time course and magnitude of the inflammatory, hepcidin and endotoxin responses evoked by exercise under hot environmental conditions in female athletes. In a randomized cross-over study design, 13 endurance trained female athletes (age 26 (range: 20-42) years; VO2max 57.7 (53.4, 62.1) mL·kg-1·min-1; mean (95% CI)) completed two exercise sessions on a treadmill at 70% VO2max in hot (35°C and 40% RH) and cool (11°C and 40% RH) environmental conditions. Peak body core temperature during the hot condition was greater than the cool condition (change +2.1°C (1.8, 2.3); +1.0°C (0.8, 1.3); p