A deterministic simulation model was developed to help assess emergency environmental needs of swine nurseries by modeling short term power interruptions. The model accounts for heat exchange by conduction, convection, radiation and air infiltration. A sub-model, developed by the North Central Region Committee 179, was used to predict swine heat and moisture loss. The model was validated using a nursery constructed of concrete block. The model performed well for cases with a constant solar load but tended to overpredict temperature changes during periods of no solar load. Validation indicated that wind velocity had the most effect upon model error. Sensitivity analysis indicated that animal body weight, long wave emissivity, net energy content of the feed, and digestible energy content were the most sensitive inputs.