The Salmonid family are cold-blooded organisms that can respond to an uncomfortable water temperature by moving from one spot to another to maintain thermal comfort. If the reason they move is because of a discrepancy between the temperature of the surrounding water and 'set point' in their brains that registers thermal comfort, their response is known as behavioral thermoregulation. In this paper the authors discuss two kinds of behavior thermoregulation: reactive and predictive. The reactive kind is in response to discomfort that is temporary and short term, and so it a response to a proximate factor, as described above. Predictive thermoregulation occurs when the temperature of the water in which salmonids choose to swim reflects their adaptation over time to a changing environment and thus is a response to an ultimate factor, as described above. Sometimes water temperature stimulates behavior that has nothing to do with thermal comfort.

"May 2001." The Project workgroup consists of individuals from U.S. Environmental Protection Agency (Region 10), U.S. Forest Service, Washington Department of Ecology, National Marine Fisheries Service, U.S. Fish and Wildlife Service, Columbia River Inter-Tribal Fish Commission, Idaho Department of Environmental Quality, U.S. Geological Survey, and Oregon Department of Environmental Quality. Microfiche.

"The technical workgroup developed five technical summaries on the major physical and biological considerations for developing water temperature standards: 1. thermal effects on salmonid physiology, 2. thermal effects on salmonid behavior, 3. interactions between multiple stressors ... affecting salmonids, 4. thermal influences on salmonid distribution, and 5. spatial and temporal variation in patterns of stream temperature."--Preface.