  In this paper, we investigate an inverse problem for the radiative transfer
equation that is coupled with a heat equation in a nonscattering medium in
$\mathbb{R}^n$, $n\geq 2$. The two equations are coupled through a nonlinear
blackbody emission term that is proportional to the fourth power of the
temperature. By measuring the radiation intensity on the surface of the
blackbody, we prove that the emission property of the system can be uniquely
reconstructed. In particular, we design a reconstruction procedure that uses
merely one set of experiment setup to fully recover the emission parameter.
