If the exposed surface area and the average outer surface temperature of the person are 2 m^2 and 20°C respectively, and the convection heat transfer coefficient is 12 W/m^2°C. The Stefan-Boltzmann coefficient is 5.67E-8 and the emissivity is 0.95. The total heat loss can be calculated using the formula:
Total heat loss = (Surface area) x (Temperature difference) x (Convection heat transfer coefficient) + (Surface area) x (Stefan-Boltzmann coefficient) x (Emissivity) x (Temperature difference)^4
Plugging in the given values:
Total heat loss = (2 m^2) x (20°C) x (12 W/m^2°C) + (2 m^2) x (5.67E-8) x (0.95) x (20°C)^4