Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. Provide a plausible expla- nation for this situation (with supporting calculations) by considering a room whose air temperature is main- tained at 20°C throughout the year, while the walls of the room are nominally at 27°C and 14°C in the sum- mer and winter, respectively. The exposed surface of a person in the room may be assumed to be at a tempera- ture of 32°C throughout the year and to have an emis- sivity of 0.90. The coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 W/m2 · K.