Hypothalamic control of thermoregulation during dehydration.

Hypothalamic control of thermoregulatory evaporation has been examined in hydrated and dehydrated cats exposed to warm ambient temperatures. Reduction in evaporative cooling during dehydration is associated with increased hypothalamic temperature. Local thermal stimulation of the hypothalamus indicates that the thermosensitivity of hypothalamic systems controlling evaporation is reduced by dehydration. These findings are discussed in relation to control system models of thermoregulation.