PROJECT SUMMARY Preclinical research relies heavily on appropriate animal models to better understand human biology and to test the safety and efficacy of new therapies. It is important that animal research cores continually strive to optimize preclinical models, both from an animal welfare standpoint and to promote rigor and the translatability of preclinical data. Rodents are thought to represent around 97% of the vertebrate animals used in biomedical research in the US. Guidelines in the US recommend housing laboratory rodents at temperatures ranging from 20°C to 26°C. However, there a growing body of data indicating that housing temperatures in the low to mid-20°Cs represents mild cold stress for rodents. Critically, compared to housing animals at thermoneutrality, sub- thermoneutrality can fundamentally change rodent physiology to a degree that can impact disease susceptibility and/or the efficacy of specific therapies. Accordingly, the utility and importantly the translational value of preclinical rodent models is dependent on appropriate control of housing temperature. The goal of this application is to acquire modern rodent housing cabinets that will advance research-related operations within the animal core at Arkansas Children’s Research Institute by providing a cost and energy- efficient means to breed, house, and study rodents at temperatures that promote the rigor and translatability of resulting data.