Thesis (M.P.E.)--Memorial University of Newfoundland, 2002. / Includes bibliographical references.

No description available.

No description available.

In the homeotherm, core body temperature (T(bc)) is considered one of the vital signs by which physiologic normality can be assessed. In persons who are unable to self-regulate T(bc), hypothermia (HT) can result. Recognition of HT as a potential physiologic problem especially in the adult postsurgical patient who is recovering from anesthesia has been acknowledged. Recovery room (RR) nurses daily manage the shivering patient who not only experiences increased oxygen demand, but who may also exhibit airway obstruction and increased somnolence as a result of HT. Thus, a primary nursing activity in the RR is to assist the patient in recovery from anesthesia and to facilitate his return toward normothermia. No study has delineated the frequency, temperature range, or duration of HT in adult RR postsurgical patients. Additionally, no data exist to support the effectiveness of current nursing heat treatments directed against mild to moderate degrees of HT. The present study addresses both of these issues. Hypothermia is defined as T(bc) of less than 36.0 degrees centigrade (°C). One hundred ninety-eight patients were randomly assigned to one of four treatment groups. Three groups received a form of external heat while the final group did not. Heat was applied with radiant heat lamps, thermal with bath blanket (warmed), and bath blankets (warmed) with change. The control group had one bath blanket at room temperature. The purposive, nonrandom sample consisted of consenting adults scheduled for various operative procedures. Previous approval for the protocol had been received from the Human Subjects Committee. In all patients requiring RR care, identifying and descriptive characteristics were recorded. Disposable tympanic membrane probes were used to assess T(bc) with measurements taken on RR admission and every 15 minutes thereafter until discharge. Descriptive statistical analyses demonstrated that 60 percent of the subjects (n = 118) were hypothermic on RR admission. Mean RR admission T(bc) and discharge T(bc) (mean ± standard error [range]) were 35.6°C ± 0.06 [32.5-37.5°C] and 36.3 ± 0.05 [33.5-38.0°C] respectively. Duration of HT averaged 47 ± 4 minutes. Eighteen percent of all subjects were discharged from the RR with T(bc) of less than 36.0°C. Among heat transfer treatment groups, one-way analysis of variance or group t-tests demonstrated no significant difference in the rate of T(bc) rise in the first hour of RR stay, T(bc) change every 15 minutes, change in T(bc) divided by RR time, or discharge T(bc). Statistical significance was set at p < .05). Aged subjects (≥ 60 years) compared to nonaged subjects (< 60 years) demonstrated significantly lower T(bc)'s on admission and throughout the mean RR stay (admission to +90 minutes; p < .05). Rate of T(bc) rise for aged subjects was not significantly different from nonaged subjects. In conclusion, RR nurses should be alert for HT in a significant number of adult postsurgical patients. Accurate monitoring of T(bc) is necessary particularly early during the RR stay. Application of the heat transfer treatments does not significantly affect T(bc). However, anesthetic type and age can significantly affect T(bc) and therefore prescribe alterations in nursing activities.

No description available.

Based on a theoretical analysis of the heat transfer process between the human body and its environment, graphs are presented for determining the theoretical skin surface temperatures and sweat rates as a function of the physiological conductance, under certain assumed environmental conditions with regard to air temperature, relative humidity and wind speed. In addition, the development of unique measuring techniques for the direct measurement of the evaporative and radiative heat transfer rates between a human body in a natural working position and its environment as well as the development of a low-cos~ radiometer for the measurement of the emissivity and temperature of human skin are described. The heat loss measuring equipment was installed in the horizontal test section of the climatic chamber of the Human Sciences Laboratory of the Chamber of Mines. Basically the evaporative heat loss measuring system consists of two air-sampling probes, for sampling the air on the upstream and downstream sides of the body , a double circuit heat exchanger, for equalising the dry- bulb temperatures of the two air samples and a differential humidity- measuring system incorporating electrical resistance hygrometero, for measuring the difference in specific humidity between the two air samples. In addition, a steam generator is provided for introducing a known amount of steam at a predetermined rate into the wake of the body. Since the output of the humidity-measuring system is linearly related to the evaporative heat loss rate, the unknown rate of evaporation of moisture from the human body can be determined relatively easily from a knowledge of the respective outputs of the humidity-measuring system due to the moisture evaporation rate of the human body and the known vapour production rate by the steam generator. The direct- measuring instrument for determining the radiation energy exchange rate of a working subject is in the form of a rotating hoop. The inside and outside surfaces of the hoop are lined with thermal radiation-sensing elements, so connected as to measure the net radiation energy exchange between the subject and the surroundings. The hoop integrates over the circular strip formed by the elements and upon rotation, integrates the radiation over the total 4n surface enveloping the subject . While the interposition of a surface between the body and its surroundings must of necessity influence the radiation exchange, the method introduces a small surface only . The significance of the evaporative and radiative heat loss measuring techniques which were successfully used in animate studies, is reflected in the, hitherto unknown, accuracy regarding partial calorimetric studies . The low- cost radiometer for measuring the skin temperature and emissivity is equipped with two non-selective thermal radiation detectors in the form of semi-conductor thermocouples. The one radiation-sensing element faces a built-in reference black body. The other detector, which can be temperature controlled, is used to detect the incoming radiation from the target. The output of the radiation-sensing elements which is sufficiently high to be measured on a recorder without the use of a chopper-amplifier system, can either be measured differentially or the output of the radiation-sensing element facing the target can be measured separately; for the purpose of temperature and emissivity measurements, respectively. The unique facility of being able to vary the temperature of the radiation detector enabled a new method of determining the emissivity of a surface to be developed. As a result, accurate measurements of the emissivities of samples of excised skin could be carried out. An improvement in the response of the radiometer would, however, be necessary for the rapid determination of the emissivity of . living skin by this means. The accuracy with which surface temperatures could be determined by means of the radiometer compared favourably with more sophisticated radiometers. / Thesis (Ph.D.)-University of Natal, Durban, 1974.

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.

The influence of photoperiod and genotype on thermal preference of juvenile Gryllus firmus was explored. Both rearing condition and genotype affect temperature preference. The following results were obtained: (1) the wing morph of juveniles raised at 28$ sp circ$C 16hL:8hD is determined before 20 days post hatching. (2) Crickets distribute themselves on the apparatus differently in the presence of a thermal gradient than in its absence: such controls for positioning preference are rare in the literature. (3) Juveniles younger than 20 days old tend to choose higher surface temperatures and achieve higher body temperatures if either rearing photoperiod or selection predisposes them to microptery and choose lower temperatures if they are predisposed towards macroptery. (4) The differences in thermal preference between presumptive macropters and micropters remains significant after differences in body size are taken into account. The differences in thermal preference could act as a novel mechanism for lowering the heritability of wing morph.

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