Abstract Introduction Burned skin excision and subsequent grafting removes sweat glands, which impairs thermoregulation. Consequently, exercise prescribed for rehabilitation may expose individuals with burn injuries to a greater risk of hyperthermia, depending on exercise duration, intensity, and environmental temperature. Little is known regarding the risk of hyperthermia in adult burn survivors performing mild/moderate-intensity exercise under thermoneutral environmental conditions, i.e. conditions similar to the rehabilitation clinic and/or the gym. This project tested the hypothesis that burn survivors, across a wide range of percent total body surface area (%TBSA) burned, can participate in mild/moderate-intensity exercise in a thermoneutral environment without excessive elevations in core body temperature. Methods Twenty-eight well-healed burn survivors with low (23±5%TBSA; N=10), moderate (42±7%TBSA; N=9), and high (60±8%TBSA; N=9) sized burn injuries performed 60 minutes of cycle ergometry exercise (72±15 Watts, oxygen uptake rate of 1.25±0.21 L/min equivalent to 4.5±0.2 METs) in a 25°C and 23% relative humidity environment. Absolute gastrointestinal temperatures (Tcore) and changes in gastrointestinal temperatures (ΔTcore) were obtained at 15-minute increments throughout the exercise bout. A participant with an absolute Tcore of greater than 38.5°C, and/or a ΔTcore of >1.5°C, at any time point during the trial was categorized as being at risk for hyperthermia. Results Sixty minutes of exercise increased Tcore in all groups (Low: 0.72±0.21°C; Moderate: 0.42±0.22°C; High: 0.77±0.25°C, all P< 0.01 from pre-exercise baseline), resulting in similar absolute Tcore values of upon exercise termination (Low: 37.87±0.24°C; Moderate: 37.56±0.34°C; High: 37.76±0.47°C, P=0.19). Importantly, no participant was categorized as being at risk for hyperthermia, based upon the aforementioned criteria. Conclusions These data indicate that individuals with substantial %TBSA burned can exercise at a mild/moderate intensity for 60 minutes in thermoneutral environmental conditions without a risk of excessive elevations in body core temperature.