Sensible and latent heat (moisture) production data were obtained for broiler chickens grown from 3 to 7 weeks of age on litter at three environmental temperatures: 15.6, 21.1, and 26.7 C. Shape of the specific sensible and latent heat curves were similar for the 15.6 and 21.1 C temperatures, but the sensible heat production at 15.6 C was about 12% greater than for 21.1 C for chickens weighing between 500 and 1000 g; the different increased for heavier chickens. Heat production curves for 26.7 C were markedly different from the other two temperatures. Specific sensible heat at 26.7 C was 2.8 cal/hr (g) and was independent of body weight over the range 500 to 1800 g. The data were compared to those published since 1969 to determine if increased growth rates have affected heat production data. Results indicate no discernible effect for cool temperatures, but for warm temperatures it appears that increased growth rates may be accompanied by an approximately proportional increase in specific sensible heat production.