Abstract: The rectal temperature (RT), water consumption and behavior of St. Croix White (n = 6; SCW) and Polypay X SCW (n = 6; PSC) lambs were evaluated under tropical conditions. Lambs were 125 d of age at the time of the behavior evaluations. Lambs were placed in partially shaded pens at 0900 and water was withheld for 4 h. Lambs were then placed individually in partially shaded pens with access to water and observed for 2 h. Animal activity, location and posture in were recorded at 5-min intervals. Immediately prior to and after the evaluation period, rectal temperature (RT) was measured in each lamb. Black bulb temperature was 34.6 and 43.6 C in the shade and sun, respectively. Hair lambs had lower RT (P < 0.005) than PSC lambs (39.6 ? .1 vs 40.1 ? .1 C, respectively). The PSC lambs consumed less water (P < 0.05) (189.2 ? 53.1 vs 355.8 ? 53.1 mL, respectively) and spent a higher (P < 0.001) proportion of time in shade than SCW lambs during the 2 h period. The elevated RT of crossbred lambs may be due in part to their lower water intake and heavier fleece even though they spent more time in the shade than the hair lambs.