The purpose of this study was to examine the independent and combined effects of thermal biofeedback and thermal suggestions on peripheral temperature control. Four treatment groups were compared: biofeedback, suggestion, combined biofeedback-suggestion, and a control group receiving only instructions requesting that the subjects attempt to raise their peripheral temperature. All groups received these same response-specific instructions. It was hypothesized that the group receiving the combined treatment would demonstrate the greatest amount of peripheral temperature control and that the control group would demonstrate the least.40 subjects participated in the study (10 per group). Before attending three treatment sessions, each subject attended two baseline sessions. Temperature change was computed from the end of a stabilization period to the end of a 15 minute training period. This temperature change on baseline days represented the subject's natural drift in peripheral temperature. Baseline day changes were subtracted from training day changes in order to control for each individual's natural drift. The resulting change scores were used as the dependent variable.A 4 X 3 ANOVA with repeated measures on the last factor was the statistical design used to analyze the data. There were no significant effects found at the .05 level. The results of this study are therefore indicative of the following conclusions:1. Biofeedback, suggestion, or a combined biofeedback, suggestion method, when used in conjunction with response-specific instructions for raising peripheral temperature, are not significantly different from each other in their effects upon peripheral temperature control. Also, the effects of these treatments on peripheral temperature control are not significantly different from the effects of a treatment consisting only of response-specific instructions.2. Regardless of treatment received, peripheral temperature control is not effected by the amount of training received over three training sessions.3. The effects of the different treatments upon peripheral temperature control is not dependent upon the amount of training received over a three session period of time.Although not significantly lower, the mean of the control group consistently demonstrated the poorest level of peripheral temperature control. All four treatment groups were able to demonstrate peripheral temperature control.

The effects of experimental variables (wind speed, fluid type, animal restraint, etc.) on the thermal time constant are analyzed. Results suggest that insufficient attention paid to these variables has resulted in equivocal results. A model is proposed that could normalize some of these variables and provide a better basis for the theoretical interpretation of reptile thermal ecology. Modelled literature data indicate that: (1) very small reptiles (20 g or less) are able to control their rates of heat exchange; (2) aquatic reptiles probably have the same ability to thermoregulate as terrestrial reptiles; (3) variations in the reported thermal time constants of turtles might reflect changes in surface area; (4) changes in humidity (without condensation) will not affect Tau; (5) constant or variable metabolic rates cannot account for differences between heating and cooling thermal time constants; (6) constant or variable metabolic rates are not likely to lead to the evolution of homeothermy.

Photocopy of typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1979. / Bibliography: leaves 200-215. / Microfiche. / xv, 215 leaves ill. 28 cm

Thermoregulation after acute ethanol, during chronic exposure and during withdrawal from ethanol dependency was studied using genetically heterogeneous (HS) mice, and lines of mice selected in replicate for smaller (HOT1, HOT2) or greater (COLD1, COLD2) decline in rectal temperature (Tre ) after intraperitoneal ethanol. First, HS mice were injected with 20% ethanol in 0.9% NaCI, or NaCI alone during sessions of behavioral thermoregulation in individual temperature gradients (9-38°C). Internal temperature (Tj ) was monitored with implanted telemetry devices. An imaging system recorded selected temperature (Tsel ) within the gradient every 5 sec. Acute 2.25 and 2.60 g ethanol/kg produced significantly lower Tj than NaCI. 2.60 g/kg also produced significantly lower Tsel than 2.25 g/kg or NaCI. 2.75 g/kg and above incapacitated mice. Comparison of responses using a thermoregulatory index indicated 2.25 or 2.60 g/kg decreased the regulated temperature. Similar methodology was followed using the selected lines and 10% ethanol (2.0, 2.25, 2.65 g/kg to COLD mice; 2.65, 2.85 g/kg to HOT mice; 3.0 g/kg to HOT2 mice) or NaCI. All responded similarly to NaCl, with transient rise in Tj After an effective ethanol dose mice manifested a regulated decrease in Tj by lowering Tsel concomitant with falling Tj . In both replicate pairs COLD mice were more sensitive than HOT, indicating that a true difference in the CNS regulator of body temperature was selected for in these animals. Photoperiod effect was characterized by quantifying thermoregulatory behavior of COLD2 mice after acute 2.60 g 7.5% ethanol/kg or NaCl, at 0400 , 0800 , 1200, 1600 , 2000 and 2400 hours , using above methodology. Baseline T₁ was significantly lower during hours of light, than during darkness. Photoperiod had little effect on thermoregulatory response to ethanol, possibly because of arousal associated with experiments. Thermoregulatory tolerance to ethanol was investigated using HS mice implanted with telemetry devices and monitored in the gradient on days 1, 2, 4, 7 and 11 of 11 consecutive days of 10% ethanol (2.75 g/kg) or NaCl injections. Dispositional, rapid and chronic tolerance developed, indicating that functional tolerance is a regulated phenomenon in mice. In a separate experiment HS mice were implanted with telemetry devices and injected with ethanol for 11 consecutive days at constant temperature; dispositional but not functional tolerance developed. To characterize thermoregulation during withdrawal, HS mice were made dependent upon ethanol using a vapor chamber; T; Tsel and activity were monitored in the gradient until 26 hours post withdrawal. Withdrawing mice showed unaltered regulated temperature, but lower Tsel than controls. This suggested increased metabolic heat production. Thermoregulation during withdrawal was similarly studied using the selected mouse lines. COLD mice responded like HS mice. Withdrawing HOT1 mice were more active than controls; withdrawing HOT2 mice showed lowest Tsel of any genotype but maintained Ti above controls. These results suggest a more severe withdrawal reaction in HOT, than in COLD mice. To investigate a possible mechanism underlying ethanol hypothermia, responses of HOT and COLD mice to intracerebroventricular serotonin were characterized. Dose-dependent decreases in Tre were measured in mice equipped with indwelling brain cannulae and held at constant temperature after injection of 0.3, 0.8, 2.0, 5.0 or 11.0 μg serotonin into the lateral brain ventricle. COLD mice were significantly more sensitive than HOT mice. Subsequently HOT1 and COLD1 mice were equipped with brain cannulae and implanted telemetry devices; thermoregulatory behavior after 11.0 μg serotonin was monitored. Both genotypes lowered Tj significantly more in the gradient than did similar mice at constant ambient temperature, indicating that decline in Tj after serotonin was a regulated phenomenon. The serotonergic system was altered during selection for differential Tre response to ethanol, indicating a role for serotonin in mediating ethanol hypothermia.

African elephants are known to survive in habitats with ambient temperatures from below 0°C to about 50°C, implying that they may be exposed to great thermal challenges, especially in hot regions of Africa, where they are common. Thermoregulatory behaviour of the African forest elephant in its natural habitat and the microclimates that it utilizes have not previously been investigated. To understand how such an enormous animal behaves in the hot, humid natural forest environment, I investigated microclimates at forest-savannah interfaces (bais) in Lobeke National Park in Cameroon, observed forest elephants’ likely thermoregulatory behaviour and correlated the behaviours with environmental microclimatic variables. Portable weather stations equipped with data loggers were deployed at five study sites to record microclimatic variables for three days per site. I used the fixed point sampling method to observe and record behaviours of forest elephants, during the hot, dry season. Black globe temperature reached an average of about 33ºC during the day in the bais and decreased to a mean of about 20ºC in the night. The day globe temperature often exceeded the body temperature of the elephants, but the vapour pressure of air was lower than that on the elephant’s skin. Therefore, at 100% humidity and estimated skin temperature of 35ºC, I assume elephants of this study lost heat by evaporation, both under the forest canopy and in the open bais. Wind speed in the bais was higher than that under the forest canopy, possibly facilitating convective heat loss from the elephants, particularly at night. Ear-flapping rate of the elephants correlated linearly and positively with dry-bulb and globe temperatures. Shade-seeking and dust-bathing only showed weak positive associations both with dry-bulb globe and temperatures. Between 06:00-24:00, elephants that were observed spent a mean of 40% of their time walking, 55% foraging, 7% shade-seeking, 45% ear-flapping, 4% dust-bathing and 9% of time performing water-related activities. The higher number of elephants in the bais at night as opposed to the numbers in the bais during the day, as revealed by the findings of this study, suggests that the forest elephant may have a more favourable mode of dumping its excess body heat in the open bais than under the forest canopy at night. All the bais and their vicinity that were investigated in this study were heavily trampled with elephant spoors, because many elephants frequently congregated in the area due the presence of nutritious herbaceous plants, mineral salts and variations in microclimates in the bai-savannah interfaces. The differences in microclimates in the bais and their vicinity may play a major role in influencing the forest elephant’s thermoregulatory behaviour. To the best of my knowledge, my study suggests for the first time that the forest elephant may use microclimates at the bai interface for thermoregulatory needs. However, my study is limited because it was executed for a short duration and over the hot dry season, and factors that may affect elephants such as physiology, the availability and quality of forage and predation risk were not included in this investigation. All these factors may have affected the accuracy of my findings. For these reasons the inferences made in this study on elephant microclimate selection would need further investigation before concrete conclusions are drawn. Expensive research cost, human safety, fear of human presence and hence alteration of elephant behaviour and the obscure nature of the equatorial forest have been recurrent issues hindering the investigation of behaviour of free-living African forest elephants. I suggest that it would be worthwhile investigating the forest elephant’s behaviour further by applying GPS/satellite telemetry, real time bio-logging and camera trap techniques, which offer a practical means to carry out an extensive study in the evergreen hot humid equatorial forest of the Congo Basin.

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Personal protective ensembles (PPE) are required for people exposed to hazard, which may prevent heat dissipation from the human body, leading to suffering from heat stress. To protect the PPE wearer from heat stress, a liquid cooling garment is widely accepted to provide personal cooling inside the PPE. For an impermeable PPE or a high humid environment, sweat evaporation is also prevented, and moisture accumulation may lead to discomfort. It is important to make sure that the liquid cooling garment removes enough heat to suppress sweat while not over-cooling the wearer. A thermoregulatory model was introduced and modified, in which the human body is divided into six parts, including the head, trunk, arms, hands, legs and feet. A whole/partial liquid cooling model, formed with a network of tubing, is developed. A thermal resistance network for the tubing system is built up and the control volume method is employed to carry out the numerical calculation. The liquid cooling model, thermoregulatory model and heat/mass transfer involved are integrated into one model, which can simulate a PPE wearer thermally interacting with the water cooling system, predict the physiological responses and ensure the wearer is free of heat stress. The mathematical model is verified by comparing its simulation results to experimental data from other researchers. This model is to be used to provide guidance to properly choose PPEs in various conditions.

In man the metabolic heat produced during physical exercise stresses the thermoregulatory system, particularly if hot, humid environmental conditions prevail. It has recently been postulated that endogenous opioids may play a role in regulating body temperature at rest and because it has also been shown that blood levels of these substances increase during exercise, the possibility exists that endogenous opioids may play a role in thermoregulation during exercise. A study was conducted in two parts to determine the thermoregulatory response during exercise with and without pharmacologic blockade of the opioid receptor. In Part I nine healthy male subjects performed 30 minutes cycling at 50 % maximal aerobic capacity in an environmentally controlled laboratory. The subjects received either placebo, 2mg or 10mg naloxone hydrochloride in a randomized double-blind crossover fashion prior to the exercise test. Rectal temperatures were recorded at one-minute intervals and cardiorespiratory parameters were measured during the test. Water loss was calculated from differences in nude body weight. In part II eight male subjects performed a graded maximal cycle ergometer test after receiving either placebo or 2mg naloxone in a randomized double-blind crossover fashion. Rectal and sublingual temperatures were recorded before and after the test and oesophageal temperature was recorded at one-minute intervals during the test. Cardiorespiratory parameters were recorded during the test. The results of Part I show that rises in rectal temperature as well as calculated water losses were similar for placebo and after the administration of both 2mg and 10mg naloxone. Similarly, during maximal exercise (Part II) the rise in rectal and oesophageal temperatures was equivalent for placebo and 2mg naloxone but sublingual temperature failed to rise during exercise following the 2mg naloxone dose. Cardiorespiratory responses did not differ between placebo and naloxone tests in both Part I and Part II of the study. These results indicate that naloxone-mediated blockade of opioid receptors does not affect rectal and oesophageal temperature responses to either submaximal or maximal exercise. Naloxone appears to selectively alter the sublingual temperature response to exercise possibly by altering local blood flow. It is concluded that insofar as naloxone induced opioid receptor blockade provides a measure of the function of the endogenous opioid system, this study suggests that the endogenous opioid system does not play a significant role in thermoregulation during exercise.