Measurement and manipulation of body temperature in rest and exercise Lennart Teunissen
The work presented in this thesis was conducted at MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, The Netherlands, in association with and supported by TNO, Behavioural and Societal Sciences, Training and Performance Innovations, Soesterberg, The Netherlands. Reading committee: Prof. dr. H.-C. Gunga Prof. dr. G. Havenith Prof. dr. M.T.E. Hopman Prof. dr. W.D. van Marken Lichtenbelt Prof. dr. E.J.W. van Someren Dr. C.J. de Ruiter Cover: Hans Bulthuis Printer: Ipskamp Drukkers, Enschede ISBN: 978-94-6191-486-6 L.P.J. Teunissen, Amsterdam 2012 All rights reserved. No part of this book may be reproduced or transmitted, in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without written permission from the author.
VRIJE UNIVERSITEIT Measurement and manipulation of body temperature in rest and exercise ACADEMISCH PROEFSCHRIFT ter verkrijging van de graad Doctor aan de Vrije Universiteit Amsterdam, op gezag van de rector magnificus prof.dr. L.M. Bouter, in het openbaar te verdedigen ten overstaan van de promotiecommissie van de Faculteit der Bewegingswetenschappen op woensdag 28 november 2012 om 11.45 uur in de aula van de universiteit, De Boelelaan 1105 door Lennart Pieter Jan Teunissen geboren te Amersfoort
promotoren: prof.dr. H.A.M. Daanen prof.dr. A. de Haan copromotor: dr. J.J. de Koning
Voor Quirine
TABLE OF CONTENTS ABBREVIATIONS... 9 GLOSSARY OF TERMS... 10 CHAPTER 1... FOUT! BLADWIJZER NIET GEDEFINIEERD. General introduction 1.1 Human body temperature 15 1.2 Core temperature determination 21 1.3 Heat stress and exercise 31 CHAPTER 2... FOUT! BLADWIJZER NIET GEDEFINIEERD. Non-invasive continuous core temperature measurement by zero heat flux CHAPTER 3... FOUT! BLADWIJZER NIET GEDEFINIEERD. Infrared thermal imaging of the inner canthus of the eye as an estimator of body core temperature CHAPTER 4... FOUT! BLADWIJZER NIET GEDEFINIEERD. Limitations of temperature measurement in the aural canal with an ear mould integrated sensor CHAPTER 5... FOUT! BLADWIJZER NIET GEDEFINIEERD. Telemetry pill versus rectal and esophageal temperature during extreme rates of exercise-induced core temperature change CHAPTER 6...125 Effect of warm-up and precooling on pacing during a 15-km cycling time trial in the heat CHAPTER 7... FOUT! BLADWIJZER NIET GEDEFINIEERD. Effects of wind application on thermal perception and self-paced performance CHAPTER 8...169 Heat strain and performance in ice hockey goalies
CHAPTER 9...185 Summarizing discussion APPENDIX...199 Core temperature measurement methods A.1 Electrical resistance 201 A.2 Infrared 209 A.3 Radio waves 212 A.4 Heat flow 214 SAMENVATTING (DUTCH SUMMARY)... 223 DANKWOORD (WORD OF THANKS)... 227 LIST OF PUBLICATIONS... 231 CURRICULUM VITAE... 232
Abbreviations ABBREVIATIONS avg = average T ac = aural canal temperature BM = body mass T amb = ambient temperature bpm = beats per minute T ax = axillary temperature C = degree Celsius T bl = bladder temperature CBF = cerebral blood flow T body = mean body temperature CNS = central nervous system T ca = temperature of the inner canthus = difference of the eye HR = heart rate T core = core temperature Hz = hertz T eb = exhaled breath temperature ICE = ice-slurry T es = esophageal temperature IR = infrared T fh = forehead temperature LoA = limits of agreement T gi = gastrointestinal temperature MRI = magnetic resonance imagery T np = nasopharyngeal temperature NIRS = near-infrared spectroscopy T or = oral temperature p = statistical significance level T pa = pulmonary artery temperature PO = power output T pill = temperature measured by r = correlation coefficient telemetry pill RH = relative humidity T re = rectal temperature RPE = rate of perceived exertion T sk = (mean) skin temperature RT = reaction time T tr = temporal radiation temperature SC = scalp cooling T ty-c = tympanic temperature measured SD = standard deviation by direct contact TC = thermal comfort T ty-ir = tympanic temperature measured TS = thermal sensation using infrared VO 2 = oxygen uptake T ur = urine temperature W = Watt T va = vaginal temperature WBGT = wet bulb globe temperature T zhf = temperature measured using ZHF = zero heat flux the zero heat flux technique 9
Glossary of terms GLOSSARY OF TERMS 1 Ambient temperature (T amb ): The average temperature of the environment surrounding a body (usually air or water), as measured outside the thermal and hydrodynamic boundary layers that overlay the body. Body heat balance: The steady-state relation in which total heat gain in the body equals its heat loss to the environment. Core temperature (T core ): Ideally, the mean temperature of the thermal core. In practice it is represented by a specified core temperature at the site of measurement. Core, thermal: Those inner tissues of the body whose temperatures are not changed in their relationship to each other by circulatory adjustments and changes in heat dissipation to the environment that affect the thermal shell of the body. Body heat content: The product of the body mass, its average specific heat, and the absolute mean body temperature. Heat flow: The amount of heat transferred per unit of time between body parts at different temperatures, or between a body and its environment when at different temperatures. Heat strain: In temperature regulators: 1. Any deviation of body temperature induced by sustained heat stress that cannot be fully compensated by temperature regulation; 2. Any activation of thermoeffector activities in response to heat stress that causes sustained changes in the state of other, non-thermal, regulatory systems. Heat stress: Any change in the thermal relation between a temperature regulator and its environment which, if uncompensated by temperature regulation, would result in hyperthermia. Homeostasis: General term characterizing the relative constancy of the internal environment of an organism as being maintained by regulation. 1 Partly from: The Commission for Thermal Physiology of the International Union of Physiological Sciences. Glossary of terms for thermal physiology. Jpn J Physiol 2001; 51(2): 245-80. 10
Glossary of terms Hyperthermia/hypothermia: The condition of a temperature regulator when core temperature is above/below its range specified for the normal active state of the species. Mean body temperature (T body ): The total temperature signal generated by all thermosensors distributed in the core and shell. Mean skin temperature (T sk ): The weighted average of a certain number of regional skin temperatures. Precooling: The artificial reduction of body heat content prior to exercise. Selective brain cooling (SBC): Lowering of brain temperature, either locally or as a whole, below aortic (arterial blood) temperature. Shell, thermal: The skin and mucosal surfaces of the body engaged directly in heat exchange with the environment. In addition, those tissues under these surfaces whose temperatures may deviate from core temperature due to heat exchange with the environment and to changes in circulatory convection of heat. Temperature regulation: The maintenance of the temperature or temperatures of a body within a restricted range under conditions involving variable internal and/or external heat loads. Thermal comfort (TC): Subjective rating on how comfortable the thermal environment is experienced. Thermal sensation (TS): Subjective rating on the sense of temperature. Thermoeffector: An organ system and its action, that affect heat balance in a controlled manner as part of the processes of temperature regulation. Thermography, infrared: The recording of the temperature distribution of a body from the infrared radiation emitted by the surface. Wet bulb globe temperature (WBGT): a composite temperature used to estimate the combined thermal stress of air temperature, humidity, wind speed and solar radiation on humans 11
Glossary of terms 12