Fig. (4) Revised curves for temperature of ambient air, air flow rate, temperature, relative humidity and CO2 concentration of exhaled breath gas for a test participant in the resting state. Te, the exhaled air temperature in °C, RHe, the exhaled air relative humidity in % M’ is the air flow rate in m3/s, Ta is the ambient air temperature in °C, CO2-e is the CO2 concentration of ambient air in ppm.