The low Mach number limit of full compressible Navier-Stokes equations with large temperature variations is verified rigorously in a three-dimensional bounded domain. Weighted uniform estimates of the solutions are derived delicately in a time interval which is independent of the Mach number, in particular, for the high-order derivatives, when the initial data are well prepared only in the sense of L2-norm.The effects of large temperature variations and solid boundaries create some essential difficulties in showing the uniform estimates. This is a recent joint work with Prof. Ou, Yaobin from Renmin University.