Theoretical Predictions of Body Tissue and Blood Temperature During Cold Water Immersion Using a Whole Body Model

2013 ◽  
Author(s):  
Anup K. Paul ◽  
Swarup A. Zachariah ◽  
Liang Zhu ◽  
Rupak K. Banerjee
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Cold Water ◽  
Water Immersion ◽  
The Body ◽  
Stress Conditions ◽  
Body Tissue ◽  
Whole Body ◽  
Transfer Model ◽  
Blood Temperature

Understanding the thermal response of the human body under various environmental and thermal stress conditions is of growing importance. Calculation of the core body temperature and the survivability of the body during immersion in cold water require detailed modeling of both the body tissue and the time-dependent blood temperature. Predicting body temperature changes under cold stress conditions is considered challenging since factors like thickness of the skin and blood perfusion within the skin layer become influential. Hence, the aim of this research was to demonstrate the capability of a recently developed whole body heat transfer model that simulates the tissue-blood interaction to predict the cooling of the body during immersion in cold water. It was shown that computed drop in core temperature agrees within 0.57 °C of the results calculated using a detailed network model. The predicted survival time in 0 °C water was less than an hour whereas in 18.5 °C water, the body attained a relatively stable core temperature of 34 °C in 2.5 hours.

scholarly journals On the heating and cooling of the body by local application of heat and cold

1922 ◽  
Vol 93 (651) ◽  
pp. 207-212
Keyword(s):  
Body Temperature ◽  
Beneficial Effect ◽  
Cold Water ◽  
The Body ◽  
Hot Water ◽  
Local Application ◽  
Whole Body ◽  
Local Cooling ◽  
Heating And Cooling ◽  
Stimulation Of

The object of this enquiry is to find out how much heat can be gained, or cold lost from the body, by the local cooling or warming of a small part, by cooling the hands in a stream of cold water, warming the feet in a hot foot­ bath, or by a foot-warmer. In order to secure the beneficial effect of open windows, the breathing of cool air of low-vapour tension, and stimulation of body metabolism by such air ventilating the clothed and naked parts of the skin, the general heating of rooms by hot-water coils might be replaced by small heaters kept a few degrees above body temperature and locally applied to each individual, and each under the individual’s control. Electric heaters have been used by aeroplanists placed beneath their outer garments. One of us(l) recently published results showing that heating or cooling the hands can effectively heat or cool the whole body. We record further experiments of a like nature.

Influence of Exercise Condition on Tissue Blood Temperature Using Whole Body Model

2013 ◽  
Author(s):  
Swarup A. Zachariah ◽  
Anup K. Paul ◽  
Rupak K. Banerjee ◽  
Liang Zhu
Keyword(s):  
Human Body ◽  
Core Body Temperature ◽  
Thermal Response ◽  
The Body ◽  
Tissue Temperature ◽  
Whole Body ◽  
Transfer Model ◽  
Blood Temperature ◽  
Exercise Condition ◽  
Core Body

Predicting thermal responses of the human body accurately during different exercise conditions is of increasing importance. Computing changes in the core body temperature (T c) during exercise require detailed modeling of both the body tissue temperature and the time-dependent blood temperature. Predicting changes in T c is challenging because the model needs to respond effectively to the changes in perfusion or sweating. Our study was to demonstrate the ability of a recently developed whole body heat transfer model. It simulates the tissue-blood interaction to predict the thermal response of the human body under different exercise intensities. The cases simulated were of a human being walking on a treadmill at 0.9, 1.2 and 1.8 m/s for 30 minutes. It was shown that T c was effectively regulated within 0.17 °C of the steady state value of 37.23 °C for the three cases by means of adjusting the cardiac output; varying between 15 to 25 liters per minute.

HEAT TRANSFER MODEL FOR PREDICTING SURVIVAL TIME IN COLD WATER IMMERSION

2005 ◽  
Vol 17 (04) ◽  
pp. 159-166 ◽  
Author(s):  
F. TARLOCHAN ◽  
S. RAMESH
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Survival Time ◽  
Cold Water ◽  
Water Immersion ◽  
Thermal Conductance ◽  
Cold Water Immersion ◽  
The Body ◽  
Complex Nature ◽  
Transfer Model

In the present paper a heat transfer (HT) model to estimate survival time of individual stranded in cold water such as at sea is proposed. The HT model was derived based on the assumption that the body specific heat capacity and thermal conductance are not time dependent. The solution to the HT model simulates expected survival time as a function of water temperature, metabolism rate, skin, muscle and fat thickness, insulation thermal conductivity and thickness, height and weight of the subject. Although, these predictions must be considered approximate due to the complex nature of the variables involved, the proposed HT model can be employed to determine supplemental body insulation such as personal protective clothing to meet a predefined survival time in any given water temperature. In particular, the results obtained are useful as a decision aid in search and rescue mission in predicting survival time for shipwreck victims at sea.

scholarly journals Seven days of cold acclimation substantially reduces shivering intensity and increases nonshivering thermogenesis in adult humans

2019 ◽  
Vol 126 (6) ◽  
pp. 1598-1606 ◽  
Author(s):  
Kyle Gordon ◽  
Denis P. Blondin ◽  
Brian J. Friesen ◽  
Hans Christian Tingelstad ◽  
Glen P. Kenny ◽  
...  
Keyword(s):  
Cold Acclimation ◽  
Core Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Metabolic Changes ◽  
Whole Body ◽  
Nonshivering Thermogenesis

Daily compensable cold exposure in humans reduces shivering by ~20% without changing total heat production, partly by increasing brown adipose tissue thermogenic capacity and activity. Although acclimation and acclimatization studies have long suggested that daily reductions in core temperature are essential to elicit significant metabolic changes in response to repeated cold exposure, this has never directly been demonstrated. The aim of the present study is to determine whether daily cold-water immersion, resulting in a significant fall in core temperature, can further reduce shivering intensity during mild acute cold exposure. Seven men underwent 1 h of daily cold-water immersion (14°C) for seven consecutive days. Immediately before and following the acclimation protocol, participants underwent a mild cold exposure using a novel skin temperature clamping cold exposure protocol to elicit the same thermogenic rate between trials. Metabolic heat production, shivering intensity, muscle recruitment pattern, and thermal sensation were measured throughout these experimental sessions. Uncompensable cold acclimation reduced total shivering intensity by 36% ( P = 0.003), without affecting whole body heat production, double what was previously shown from a 4-wk mild acclimation. This implies that nonshivering thermogenesis increased to supplement the reduction in the thermogenic contribution of shivering. As fuel selection did not change following the 7-day cold acclimation, we suggest that the nonshivering mechanism recruited must rely on a similar fuel mixture to produce this heat. The more significant reductions in shivering intensity compared with a longer mild cold acclimation suggest important differential metabolic responses, resulting from an uncompensable compared with compensable cold acclimation. NEW & NOTEWORTHY Several decades of research have been dedicated to reducing the presence of shivering during cold exposure. The present study aims to determine whether as little as seven consecutive days of cold-water immersion is sufficient to reduce shivering and increase nonshivering thermogenesis. We provide evidence that whole body nonshivering thermogenesis can be increased to offset a reduction in shivering activity to maintain endogenous heat production. This demonstrates that short, but intense cold stimulation can elicit rapid metabolic changes in humans, thereby improving our comfort and ability to perform various motor tasks in the cold. Further research is required to determine the nonshivering processes that are upregulated within this short time period.

Comparison of core threshold temperatures for forehead sweating based on esophageal and rectal temperatures

1993 ◽  
Vol 71 (8) ◽  
pp. 597-603 ◽  
Author(s):  
Matthew D. White ◽  
Igor B. Mekjavić
Keyword(s):  
Skin Temperature ◽  
Core Temperature ◽  
Cold Water ◽  
Water Immersion ◽  
Phase 1 ◽  
Rate Of Change ◽  
The Body ◽  
Continuous Assessment ◽  
The Core ◽  
Threshold Temperatures

A protocol incorporating successive hot and cold water immersions, causing respective warming and cooling of the body, has been used to determine the core threshold for sweating. Disparate results have been reported for the core threshold of sweating, and these have been attributed to the possible existence of core temperature gradients during such a protocol. Spatial and temporal core temperature (Tc, °C) gradients during dynamic changes in body temperature may give rise to different values of core temperature thresholds for sweating, depending on the Tc measurement site. In addition, during such an immersion protocol skin temperature transients may influence expression of thresholds using esophageal temperature (Tes). With these considerations, the effects of Tc gradients and skin temperature on Tc thresholds for sweating were examined. Subjects (n = 22) were immersed to the neck in 40 °C water until Tes reached 38.5 °C (phase 1), followed immediately by cooling in 30.6 °C water until extinction of sweating was observed (phase 2). Cooling was continued in the latter bath after the sweating extinction until total immersed time reached 50 min or until shivering was initiated (phase 3). During the trials continuous assessment was made of rectal temperature (Tre) and Tes, mean unweighted skin temperature (Tsk, °C), forehead sweating rate ([Formula: see text], g∙m−2∙min−1) oxygen consumption ([Formula: see text], L∙min−1), and surface heat flux ([Formula: see text], W∙min−2). With the current protocol it appeared inappropriate to determine the Tc thresholds for onset of sweating, as sweating was initiated prior to any significant displacement of Tc, but was most likely influenced by Tsk and its rate of change. During the transfer to the 30.6 °C bath Tes followed a similar profile and rate of response as Tsk, suggesting it was affected by transient Tsk changes, whereas the rate of Tre response was significantly different than rates of skin and esophageal temperatures. Significantly different rates of Tes and Tre gave Tc gradients during such a protocol and it is concluded that this may confound determination of Tc thresholds using such a protocol.Key words: temperature regulation, hypothermia, hyperthermia, water immersion.

Heat balance precedes stabilization of body temperatures during cold water immersion

2003 ◽  
Vol 95 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Peter Tikuisis
Keyword(s):  
Heat Balance ◽  
Cold Water ◽  
Water Immersion ◽  
Heat Content ◽  
Cold Water Immersion ◽  
The Body ◽  
Body Temperatures ◽  
Mean Body Temperature ◽  
The Core ◽  
Region Temperature

Certain previous studies suggest, as hypothesized herein, that heat balance (i.e., when heat loss is matched by heat production) is attained before stabilization of body temperatures during cold exposure. This phenomenon is explained through a theoretical analysis of heat distribution in the body applied to an experiment involving cold water immersion. Six healthy and fit men (mean ± SD of age = 37.5 ± 6.5 yr, height = 1.79 ± 0.07 m, mass = 81.8 ± 9.5 kg, body fat = 17.3 ± 4.2%, maximal O2 uptake = 46.9 ± 5.5 l/min) were immersed in water ranging from 16.4 to 24.1°C for up to 10 h. Core temperature (Tco) underwent an insignificant transient rise during the first hour of immersion, then declined steadily for several hours, although no subject's Tco reached 35°C. Despite the continued decrease in Tco, shivering had reached a steady state of ∼2 × resting metabolism. Heat debt peaked at 932 ± 334 kJ after 2 h of immersion, indicating the attainment of heat balance, but unexpectedly proceeded to decline at ∼48 kJ/h, indicating a recovery of mean body temperature. These observations were rationalized by introducing a third compartment of the body, comprising fat, connective tissue, muscle, and bone, between the core (viscera and vessels) and skin. Temperature change in this “mid region” can account for the incongruity between the body's heat debt and the changes in only the core and skin temperatures. The mid region temperature decreased by 3.7 ± 1.1°C at maximal heat debt and increased slowly thereafter. The reversal in heat debt might help explain why shivering drive failed to respond to a continued decrease in Tco, as shivering drive might be modulated by changes in body heat content.

A second postcooling afterdrop: more evidence for a convective mechanism

1992 ◽  
Vol 73 (4) ◽  
pp. 1253-1258 ◽  
Author(s):  
G. G. Giesbrecht ◽  
G. K. Bristow
Keyword(s):  
Core Temperature ◽  
Initial Rate ◽  
Treadmill Exercise ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Probable Mechanism ◽  
Warm Bath ◽  
Male Subjects ◽  
Shivering Thermogenesis

An attempt was made to demonstrate the importance of increased perfusion of cold tissue in core temperature afterdrop. Five male subjects were cooled twice in water (8 degrees C) for 53–80 min. They were then rewarmed by one of two methods (shivering thermogenesis or treadmill exercise) for another 40–65 min, after which they entered a warm bath (40 degrees C). Esophageal temperature (Tes) as well as thigh and calf muscle temperatures at three depths (1.5, 3.0, and 4.5 cm) were measured. Cold water immersion was terminated at Tes varying between 33.0 and 34.5 degrees C. For each subject this temperature was similar in both trials. The initial core temperature afterdrop was 58% greater during exercise (mean +/- SE, 0.65 +/- 0.10 degrees C) than shivering (0.41 +/- 0.06 degrees C) (P < 0.005). Within the first 5 min after subjects entered the warm bath the initial rate of rewarming (previously established during shivering or exercise, approximately 0.07 degrees C/min) decreased. The attenuation was 0.088 +/- 0.03 degrees C/min (P < 0.025) after shivering and 0.062 +/- 0.022 degrees C/min (P < 0.025) after exercise. In 4 of 10 trials (2 after shivering and 2 after exercise) a second afterdrop occurred during this period. We suggest that increased perfusion of cold tissue is one probable mechanism responsible for attenuation or reversal of the initial rewarming rate. These results have important implications for treatment of hypothermia victims, even when treatment commences long after removal from cold water.

scholarly journals Effect of Drinking Hot or Cold Water and Intaking Hot Meal on the Body Temperature Measured by Ear Drum. Meaning of ONPUKU.

1994 ◽  
Vol 44 (4) ◽  
pp. 583-587
Author(s):  
Minoru HIGASA ◽  
Iwao YAMAMOTO ◽  
Ichiro NARIKAWA
Keyword(s):  
Body Temperature ◽  
Cold Water ◽  
The Body

scholarly journals Safe Duration Of A Person Soaking Inside A Hot Tub: Theoretical Prediction of Temperature Elevations in Human Bodies Using A Whole Body Heat Transfer Model

2020 ◽  
Author(s):  
Myo Min Zaw ◽  
Manpreet Singh ◽  
Ronghui Ma ◽  
Liang Zhu
Keyword(s):  
Heat Transfer ◽  
Human Body ◽  
Energy Balance Equation ◽  
The Body ◽  
Whole Body ◽  
Equation Modeling ◽  
Transient Temperature ◽  
Transfer Model ◽  
Bioheat Equation ◽  
Arterial Blood

In this study, we first develop a whole body model based on measurements of a human body, with realistic boundary conditions incorporated before and after a person jumps into a hot tub. For the transient heat transfer simulation, the initial condition is the established steady state temperature field of the human body with appropriate clothing layer to ensure the thermal equilibrium of the body with its surroundings. Once the person is inside a hot tub, the Pennes bioheat equation is used to simulate the transient temperature elevations of the body, and the rising of the arterial blood temperature is solved by an energy balance equation modeling thermal exchange between body tissue and the blood in the body. The safe duration of soaking in hot tubs is then determined as affected by the hot tub water temperatures.

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