Fig. 6. Respiratory rate in mice breathing hydrogen sulfide (H2S; 80 ppm) for 6 h at ambient temperature (Ta) 27°C ( closed hexagons , n = 4) or Ta35°C ( open hexagons , n = 4), followed by a 2-h recovery period breathing air at Ta27°C. * P < 0.05 versus time 0. § P < 0.05 versus same time point in Ta27°C group.