A person with $1.7\ \text{m}^2$ of skin at $34\ ^\circ\text{C}$ sits in a room whose walls are at $22\ ^\circ\text{C}$. The skin's emissivity is $0.90$. What net power does the person lose by radiation? ($\sigma = 5.67 \times 10^{-8}\ \text{W m}^{-2}\text{K}^{-4}$.)