title: Characteristics of hyperthermia-induced hyperventilation in humans.
abstract: In humans, hyperthermia leads to activation of a set of thermoregulatory responses that includes cutaneous vasodilation and sweating. Hyperthermia also increases ventilation in humans, as is observed in panting dogs, but the physiological significance and characteristics of the hyperventilatory response in humans remain unclear. The relative contribution of respiratory heat loss to total heat loss in a hot environment in humans is small, and this hyperventilation causes a concomitant reduction in arterial CO2 pressure (hypocapnia), which can cause cerebral hypoperfusion. Consequently, hyperventilation in humans may not contribute to the maintenance of physiological homeostasis (i.e., thermoregulation). To gain some insight into the physiological significance of hyperthermia-induced hyperventilation in humans, in this review, we discuss 1) the mechanisms underlying hyperthermia-induced hyperventilation, 2) the factors modulating this response, and 3) the physiological consequences of the response.
authors.affiliation: Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan; Department of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan.
authors.forename: Bun
authors.initials: B
authors.lastname: Tsuji
authors.affiliation: Junior College, University of Shizuoka , Shizuoka, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Faculty of Human Development, Kobe University , Kobe, Japan.
authors.forename: Narihiko
authors.initials: N
authors.lastname: Kondo
authors.affiliation: Institute of Health and Sport Sciences, University of Tsukuba , Tsukuba City, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishiyasu
keywords: Hyperpnea; heat loss; respiratory alkalosis