 Depends on the research that you look, somewhere between 75 and 77 degrees Fahrenheit, they start to get heat stress. And the interesting thing, not only does heat stress decrease their intakes, but it also increases their metabolic demand. Thursday, Beverly Hampton Pfeiffer, Senior Director with PHARM. What were some of the standards that were featured in the animal care update? We really looked and saw a lot of beefing up, for the lack of a better word, in version 3 and version 4.