An RF transmitter (10) includes an RF amplifier (22) that experiences gain-droop distortion as a result of self-heating. A heat compensator (20) is included to insert a gain boost of an amount which is the inverse of the gain droop experienced by the RF amplifier (22). The amount of gain boost is determined by generating a heat signal (88) from low-pass filtering (86) the squared magnitude (82) of a communication signal (14). The heat signal (88) is scaled by a weighting signal (68) estimated by monitoring the amplified RF signal (42) at the output of the RF amplifier (22). A nonlinear relationship section (96) then transforms the scaled signal into a gain-boost signal (94) that corresponds to the inverse of gain droop in the RF amplifier (22).