Temperature Regulation In Man Research Articles

Three-phase-lag bioheat transfer model and its validation with experimental data

In this study, we introduce a three-phase-lag (TPL) bioheat transfer model for living biological tissue by considering the heat conduction law that includes heat flux, temperature gradient and thermal displacement gradient, among the constitutive relation. The formulated TPL bioheat model is an extension of bioheat transfer models proposed by Pennes, Cattaneo-Vernotte and Tzou. The semi-analytical method has been used for the solution of TPL bioheat transfer model and this model is validated with experimental data [Stolwijk, J. A. J., and J. D. Hardy. 1966. Temperature regulation in man: a theoretical study. Pflugers Archiv Fur Die Gesamte Physiologie Des Menschen Und Der Tiere 291(2):129–62]. The phase lag times due to heat flux, temperature gradient and thermal displacement gradient is semi analytically investigated and it is found that phase-lag due to thermal displacement gradient affects significantly on temperature distribution in tissue. The semi-analytical solution has been verified with a numerical solution. The effect of parameters, such as lagging times, blood perfusion rate, metabolic heat source term and TPL parameter on tissue temperature is also discussed in detail. Highlights Three-phase-lag bioheat transfer model has been introduced for the study of heat transfer in living biological tissue. The semi analytical method has been used for the solution of the TPL model. Proposed model is validated with experimental data. The formulated TPL model is more accurate than other existing models.

Thermal pleasantness and temperature regulation in man

The temperature regulation system of man is complex and has not yet been fully understood. The “black box” is the nature of the set point which the system is known to defend. The set point is in fact a rhythmic function of time of day. Temperature-regulatory behaviour, more than autonomous response, has recently been confirmed as the dominant, effective and more sensitive control response tending to maintain body temperature close to the set point. It is possible to estimate the set point by a procedure involving a behavioural indicator, namely thermal pleasantness sensation. A number of examples are discussed in which the set point was determined by the aid of thermal alliesthesial response (i.e., change of thermal pleasantness sensation for the same stimulus according to the internal thermal state of the subject). The quantification of the set point is shown to be relevant for medical research and practice.

A contribution to the topography of temperature regulation in man.

By means of climatic chamber studies the steady-state curves of body temperature and effector mechanisms of temperature regulation in man are determined for different areas of the body. Under cold conditions local temperature differences are considerable, whereas under warm conditions, the distribution of body heat is much more uniform. Evaporative heat loss, directly measured, and skin blood flow, recorded by the fluvographic method, show considerable local differences under the influence of environmental temperature. This should be the consequence of a "distributed parameter control strategy", which may be adapted to special requirements, such as exercise or partial thermal stress of the body. The experimental results form the basis for a mathematical model of human temperature regulation, and for further experimental studies which are devoted to clarifying the strategy of regulation with local distributed parameters.

A study of the nycthemeral cycle of behavioural temperature regulation in man.

1. Four human subjects were rendered hyperthermic and hypothermic by immersion in warm and cool water, at 02.00, 08.00, 14.00 and 20.00 hr. Bath and oesophageal temperatures and pulse rate were recorded. Temperature preference was determined by operant behaviour and vote. The core temperature set-point for behavioural thermoregulation was estimated from the behavioural results. 2. The results are in accord with those of previous studies of the nyethemeral cycling of autonomic responsiveness to heat and cold with a heating up phase before noon and a cooling down phase during the early night. 3. Subjective sensations and behavioural responses were also found to follow a nycthemeral cycle with a minimum before noon and a maximum at 20.00 hr. 4. The core temperature set point was 0-7 degrees C higher after noon than before noon with a small phase advance from resting core temperature. This result suggests that the nycthemeral cyclic change in body temperature is due to a nycthemeral cyclic change in the set-point near to which body temperature is kept by both autonomic and behavioural thermoregulatory responses.

Thermal Protection for Divers

Beckman, E. L., Protection During Immersion in Cold Water, AD601044, March 1964, Naval Medical Research Inst., Bethesda, Md. Tauber, J. F. and Rawlins, J. S., Thermal Requirements for the Mark II Diving System, AD694013, 1964, Naval Medical Research Inst., Bethesda, Md. Beckman, E. L., Protective Suits for Underwater Swimmers, Rep. 8, 1967, Naval Medical Research Inst., Bethesda, Md. Bowen, H. M. and Pepler, R. D., Studies of the Performance Capabilities of Divers: The of Cold, SSD 67-399, March 1967, Dunlap and Associates, Darien, Conn. McQueen, J. D., Effects of Cold on the Nervous System, The Physiology of Induced Hypothermia, edited by R. D. Dripps, NAS-NRC Publ. 451,1956, NASA. Martorano, J. J., of Dress Suits in Maintaining Body in Cold Water, AD-265907, Oct. 1961, U.S. Naval Medical Field Research Lab., Camp Lejeune, N.C. Stolwijk, J. A. J. and Hardy, J. D., Temperature Regulation in Man—a Theoretical Study, Pfluger Archiu. Ges. Physiologic, Vol. 291, Pt. 2, 1966, pp. 129-162. Stolwijk, J. A. J. and Cunningham, D. J., Expansion of a Mathematical Model of Thermoregulation to Include High Metabolic Rates, NASA CR-092443, 1968, John B. Pierce Foundation, New Haven, Conn. Stolwijk, J. A. J., Expansion of a Mathematical Model of Thermoregulation to Include High Metabolic Rates, NASA CR102191,1969, John B. Pierce Foundation, New Haven, Conn. Stolwijk, J. A. J., A Mathematical Model of Physiological Regulation in Man, NAS-9-9531, 1970, John B. Pierce Foundation, New Haven, Conn. Craig, A. B., Jr. and Dvorak, M., Regulation During Water Immersion, Journal of Applied Physiology, Vol. 21, Pt. 5,1966, pp. 1577-1585. Reeves, E., Stephens, M. P., and Beckman, E. L., An Evaluation of the Foamed Neoprene Diver's Wet Suit as a Survival Garment for Helicopter Aircrews, Research Rept. 7, Project MF-011.99-1001,1963, Naval Medical Research Institute. Barsell, A. W., Montgomery, L. D., and Arnold, J. E., Behavior of SNAP Reactor Fuel Elements During Atmospheric Reentry, Atomics International, Div. of Rockwell International, NAA-SR-11502, 1966. Sherwood, T. K. and Reed, C. E., Applied Mathematics in Chemical Engineering, McGraw-Hill, New York, 1939.

Control of Heat Exchanges: An Alternate Concept for Temperature Regulation in Man

A model of the thermoregulatory mechanisms of man subjected to a heat load is presented. It is based on the hypothesis that the thermoregulatory system controls mainly the level of body heat storage but not the deep body temperature. The thermoregulatory system would thus appear to be a “feedback control system” of the thermal exchanges rather than a “regulator” of the deep body temperature.

Exercise temperature regulation in man during hypohydration and hyperhydration.

Human body temperature regulation under various hydration regimes during exercise, noting changes related to sweating

Exercise temperature regulation in man in the upright and supine positions

Rectal (Tre), auditory canal (Tac) and mean skin (T̄sk) temperatures and various metabolic measurements were taken on five men during 70-min exercise periods, in the upright and supine positions, on a bicycle ergometer at an average relative Vo2 of 43%. The men were tested under the four combinations of continuous and intermittent (30 sec work-rest cycles) exercise in the upright and supine positions. The purpose was (a) to confirm the elevated Tre with intermittent work; (b) to determine if these higher core temperatures were due to orthostatic reactions; and (c) to determine if the intermittent mode and/or the supine position would modify exercise temperature regulation. In all four experiments sweat rate and energy production were the same. In the upright position equilibrium Tre during intermittent work was 0.13°C higher than in continuous work; in the supine position the comparable intermittent Tre was elevated 0.28°C. The greatest increase in Tre (+ 1.56°C) occurred during the intermittent-supine experiment where the decrease in Tsk (— 0.67°C) was least. Equilibrium Tsk was elevated 0.75°C in the supine position. With similar sweat rates, intermittent exercise results in increased Tre while the supine position includes higher Tsk. The elimination of orthostatic reactions with supine exercise does not attenuate the higher intermittent work Tre. The results indicate nonlinear relationships between sweating and core and skin temperatures and suggest the action of undefined thermal and/or nonthermal inputs in the control of exercise temperature regulation.

A physiological scheme and mathematical model of temperature regulation in man.

Mean skin temperatures, rectal temperatures and sweat rates were measured on four highly acclimatised subjects. They were exposed for 180 min to 16 different combinations of 4 metabolic rates and 4 air temperatures, ranging from cold (10°C) to hot (49°C). Mean sweat rates for the second hour were plotted against mean rectal temperaturesfor 4 different levels of skin temperature and viceversa. These graphs indicate, firstly, that sweat rate does not increase until rectal temperature rises above a threshold value of 36.5°C; thereafter the increase in sweat rate depends upon the level of mean skin temperature, being greater the higher the mean skin temperature is. Secondly, sweat rate does not increase markedly until mean skin temperature rises above 33°C but the increase in sweat rate above 33°C depends upon the level of rectal temperature, being greater the higher the rectal temperature is. The interrelated effects upon sweat rate of mean skin temperature and core temperature can be explained by means of a relatively simple physiological system, comprising temperature sensors in the hypothalamus and skin, and a heat loss and a heat conservation integrating centre. Mathematical equations have been developed to express the relationships between sweat rate, core, and mean skin temperature for cool conditions, but these relationships are so complex that it is preferable to use an analogue computer for these purposes.

Nocturnal body temperature regulation in man: a rationale for sweating in sleep.

ArticleNocturnal body temperature regulation in man: a rationale for sweating in sleep.E H Geschickter, P A Andrews, and R W BullardE H Geschickter, P A Andrews, and R W BullardPublished Online:01 Mar 1966https://doi.org/10.1152/jappl.1966.21.2.623MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByWellcome Open Research, Vol. 6Turn it off and on again: characteristics and control of torpor29 March 2022 | Wellcome Open Research, Vol. 6Analysis and management of sleep dataPhotoperiod Impact on a Sailor’s Sleep-Wake Rhythm and Core Body Temperature in Polar EnvironmentWilderness & Environmental Medicine, Vol. 30, No. 4Skin temperature, sleep, and vigilanceThermoregulation in Sleep and HibernationControl of the Cutaneous Circulation by the Central Nervous System13 June 2016Isolated motor phenomena and symptoms of sleepBody Temperature, Sleep, and HibernationTemperature, Thermoregulation, and SleepSleep propensity is modulated by circadian and behavior-induced changes in cutaneous temperatureJournal of Thermal Biology, Vol. 29, No. 7-8Functional link between distal vasodilation and sleep-onset latency?Kurt Kräuchi, Christian Cajochen, Esther Werth, and Anna Wirz-Justice1 March 2000 | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, Vol. 278, No. 3MORE THAN A MARKER: INTERACTION BETWEEN THE CIRCADIAN REGULATION OF TEMPERATURE AND SLEEP, AGE-RELATED CHANGES, AND TREATMENT POSSIBILITIES7 July 2009 | Chronobiology International, Vol. 17, No. 3A short-term poikilothermic period occurs just after paradoxical sleep onset in humans: characterization changes in sweating effector activityJournal of Sleep Research, Vol. 6, No. 4Descriptive Epidemiology of Sweating in a Hospice Population8 April 2019 | Journal of Palliative Care, Vol. 13, No. 1Heat Stress and Behavior1 January 2011Nocturnal temperature and subcutaneous blood flow in humansClinical Physiology, Vol. 15, No. 6Energy conservation and sleepBehavioural Brain Research, Vol. 69, No. 1-2Skin sympathetic nerve activity and effector function during sleep in humansActa Physiologica Scandinavica, Vol. 151, No. 3Classification of Sleep DisordersMelatonin and Maturation of Rem Sleep7 July 2009 | International Journal of Neuroscience, Vol. 63, No. 1-2The Effect of Afternoon Body Heating on Body Temperature and Slow Wave SleepPsychophysiology, Vol. 27, No. 5Thermal exchanges during sleep in anhidrotic ectodermal dysplasiaEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 59, No. 6Influence of repeated passive body heating on subsequent night sleep in humansEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 59, No. 1-2Continuous Transepidermal Water Loss Measurement in Sleeping InfantsActa Paediatrica, Vol. 76, No. 3Changes in the brain and core temperatures in relation to the various arousal states in rats in the light and dark periods of the dayPflügers Archiv, Vol. 404, No. 1Thermoregulation and SleepCircadian control of body temperatureJournal of Thermal Biology, Vol. 8, No. 1-2Diurnal changes of thermoregulatory functions in pigeonsPfl�gers Archiv European Journal of Physiology, Vol. 386, No. 2Diurnal changes of thermoregulatory functions in pigeonsPfl�gers Archiv European Journal of Physiology, Vol. 386, No. 2Behavioral phenomenology of sleep (somatic and vegetative)1 January 1980 | Experientia, Vol. 36, No. 1Temperature Regulation during Sleep: A Study in HomeostasisSleep as an Adaptation for Energy Conservation Functionally Related to Hibernation and Shallow TorporCircadian change of sweating rate measured locally by the resistance hygrometry method in manExperientia, Vol. 35, No. 5Sleep and Torpor—Homologous Adaptations for Energy ConservationSLEEP AND HIBERNATION: ELECTROPHYSIOLOGICAL AND THERMOREGULATORY HOMOLOGIESCentral Nervous Regulation of Body Temperature During SleepScience, Vol. 194, No. 4264DAY-NIGHT VARIATION IN HEAT BALANCETransmission Processes Between Clock and ManifestationsThermal Conductance in Man: Its Dependence on Time of Day and on Ambient TemperatureBilan thermique de l'homme en ambiance control�e pendant 24 heuresPfl�gers Archiv European Journal of Physiology, Vol. 335, No. 2Einflu� erh�hter Raumlufttemperatur auf Herzschlagfrequenz, Bewegungsh�ufigkeit, Rectaltemperatur und Elektroencephalogramm schlafender MenschenInternationales Archiv f�r Arbeitsmedizin, Vol. 28, No. 3Drugs and Body TemperatureDie minimale W�rmedurchgangszahl des Menschen am Tage und in der NachtPfl�gers Archiv f�r die Gesamte Physiologie des Menschen und der Tiere, Vol. 295, No. 2 More from this issue > Volume 21Issue 2March 1966Pages 623-30 https://doi.org/10.1152/jappl.1966.21.2.623PubMed5934471History Published online 1 March 1966 Published in print 1 March 1966 Metrics

Temperature regulation in man--a theoretical study.

For purposes of theoretical analysis of experimental results and evaluation of hypothetical concepts a mathematical model of thermoregulation in man is presented. The human body is represented by three cylinders: the head, the trunk, and the extremities. Each cylinder is divided into two or more concentric layers to represent anatomical and functional differences in so far as they are of primary importance in thermoregulation. Heat flow between adjacent layers is by conduction, and all layers exchange heat by convection with a central blood compartment. All three skin layers exchange heat with the environment by conduction, convection, radiation, and evaporation. Signals which are proportional to temperature deviations in the brain and to deviations in average skin temperature are supplied to the regulator portion of the model. The regulator then causes evaporative heat loss, heat production by shivering or changes in the peripheral blood flow to occur in the appropriate locations in the body. If a proposed mechanism of thermoregulation is expressed in quantitative form it describes the relationships between the input signals and the resulting thermoregulatory response; the model can be used to compare the quantitative response resulting from a proposed mechanism with the responses obtained by measurement. A number of experimental results are compared with predictions furnished by the mathematical model using a regulator with an output which is proportional to the product of the input signals. It is emphasized that models of this type should be used in close connection with an experimental program to attain their full usefulness.

Climatometer and Temperature Regulation in Man

Climatometer and Temperature Regulation in Man

TEMPERATURE IN THE EXTERNAL AUDITORY MEATUS AS AN INDEX OF CENTRAL TEMPERATURE CHANGES.

The temperature of the wall of the external auditory meatus has been investigated. Changes in ear temperature reflect changes of sublingual temperature quite accurately and are well correlated with cutaneous vasomotor responses induced by body heating. The temperature of the external auditory meatus is little affected by reflex vasomotor changes. It is easily measured without discomfort or danger and provides a valid indication of temperature changes at the central receptors. There is a considerable temperature gradient down the wall of the meatus so that absolute temperature levels are probably not of value. ear temperature in man; central temperature regulation in man Submitted on February 24, 1964

Temperature: Its Measurement and Control in Science and Industry. Vol. 3 Part 3–Biology and Medicine

Only a few pages of this excellent handbook deal directly with the measurement of temperature. Most of the 56 articles which make up the text are concerned with the biological effects of heat or cold and with the mechanisms of temperature regulation in man and other species.

Electrical Analog Simulation of Temperature Regulation in Man

Using the basic equations for heat balance which have been developed to take into account heat losses by radiation, convection and evaporation, an electrical analog has been constructed to simulate the physiological responses to heat and cold in the nude man. As has been previously shown, physiologic temperature regulation involves three of the basic types of control modes, namely, proportional control, rate control, and some of the characteristics of on-off control. The rate and proportionality constants have been determined experimentally on the assumption that the regulated temperature is the average body temperature. Time constants for the various thermal changes can be determined from the thermal constants of tissue and the response times of the physiological variables of sweating, vasomotor activity and change in metabolic rate. The simulator predicts steady-state situations of rectal temperature, skin temperature, metabolic rate, vasomotor state and evaporative heat loss under both resting conditions and exercise. Dynamic responses to sudden shifts in environmental temperature, air velocity, relative humidity and metabolic rate can be simulated to a considerable extent using equations based on the controls outlined above.

The effects of hexamethonium bromide on temperature regulation in man.

The effects of hexamethonium bromide on temperature regulation in man.

Physical Basis of Temperature Regulation in Man

Physical Basis of Temperature Regulation in Man