Temperature relations of colonies of Bombus borealis, B. rufocinctus, and B. fervidus were studied in domiciles, including wooden box, clay flower pot, drainage tile, and metal can types. Each domicile had thermocouples placed under the comb, in the brood comb, on the surface of the brood comb, in the domicile but outside the nest, and outside the domicile. Representative graphs are presented to show that the bumble bees maintain brood temperatures between 80[degree] -92[degree]F. Narrower fluctuations were shown with stronger colonies, but as few as 10 worker bees were able to control brood temperatures effectively. All of the domiciles studied insulated the nest sufficiently to aid the bees, but a metal can in a metal jacket overheated readily and the bees were unable to control the violent temperature fluctuations within it.