scholarly journals One size does not fit all: Assuming the same normal body temperature for everyone is not justified

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245257
Author(s):  
Adele Diamond ◽  
Carolyn T. Lye ◽  
Deepali Prasad ◽  
David Abbott
Keyword(s):  
Individual Differences ◽  
Body Temperature ◽  
Time Of Day ◽  
Oral Temperature ◽  
Menstrual Phase ◽  
Temperature Changes ◽  
Doctor Visits ◽  
Mean Temperature ◽  
Accurate Indication ◽  
Thermal Variability

Despite the increasing personalization of medicine, surprisingly ~37.0°C (98.6°F) continues as the estimate of normal temperature. We investigated between-subject and within-subject thermal variability, whether a significant percentage of individuals have a low mean oral temperature, and whether these differ by sex, age, time of day, ethnicity, body mass index (BMI), or menstrual phase. Oral temperature was measured by Life Brand® Fast-Read Digital Oral Thermometers and sampled 14 times over two weeks, seven morning and seven evening readings. The volunteer sample consisted of 96 adults (42 men, 54 women; 27 couples, 42 singletons), ages 18–67 years. We found sizeable individual differences in body temperature and that the normal temperature of many individuals is considerably lower than 37.0°C (98.6°F). Mean temperatures ranged from 35.2°C (95.4°F) to 37.4°C (99.3°F). The mean temperature across all participants was 36.1°C (97.0°F)—lower than most studies have reported, consistent with recent evidence of temperature declining over decades. 77% had mean temperatures at least 0.55°C (1°F) lower than 37.0°C (98.6°F). Mean temperature did not differ by age, but women had higher temperatures than men, even within a couple with room temperature and warmth of clothing equated. Although oral temperature varied widely across individuals, it showed marked stability within individuals over days. Variability of temperature over days did not differ by sex, but was larger among younger adults. Using 37.0°C (98.6°F) as the assumed normal temperature for everyone can result in healthcare professionals failing to detect a serious fever in individuals with a low normal temperature or obtaining false negatives for those individuals when using temperature to screen for COVID-19, mistaking their elevated temperature as normal. Some have called for lowering the estimate of normal temperature slightly (e.g., 0.2°C [0.36°F]). That still seems an overly high estimate. More important, using any standardized “normal” temperature will lead to errors for many people. Individual differences are simply too great. Personalizing body temperature is needed. Temperature could be measured at yearly doctor visits, as blood pressure is now. That would be simple to implement. Since our results show marked thermal stability within an individual, sampling temperature only once yearly could provide an accurate indication of a person’s normal temperature at that time of day. Such records over time would also provide a more accurate understanding of how temperature changes over the lifespan.

Mouse strain differences in ozone dosimetry and body temperature changes

1997 ◽  
Vol 272 (1) ◽  
pp. L73-L77 ◽  
Author(s):  
R. Slade ◽  
W. P. Watkinson ◽  
G. E. Hatch
Keyword(s):  
Body Temperature ◽  
Mouse Strain ◽  
Strain Differences ◽  
Basal Metabolism ◽  
Temperature Changes ◽  
Mean Temperature ◽  
Body Core ◽  
Mouse Strain Differences ◽  
Delivered Dose

Strain differences in susceptibility to inhaled ozone (O3) have been observed in mice, with C57BL/6J (B6) mice reported to be more sensitive than C3H/HEJ (C3) mice when exposed to equal concentrations of O3. To determine whether differences in the delivered dose of O3 to the lung could help explain these differences, C3 and B6 mice were exposed to 18O-labeled ozone (18O3), and the resulting 18O concentrations in pulmonary tissues were monitored as an indicator of O3 delivered dose. Body core temperatures (Tco) of similarly treated mice were measured during O3 exposures (using surgically implanted temperature probes) in an effort to correlate lung O3 dose to changes in basal metabolism. Immediately after exposure to 18O3, C3 mice had 46% less 18O (per mg dry wt) in lungs and 61% less in tracheas than B6 mice. Nasal 18O tended to be lower in the C3 mice, but these differences were not significant. Although both strains responded to the O3 exposure with significant decreases in Tco, C3 mice had a 70% greater mean temperature x time product decrease during the exposure than B6 mice. These results suggest that the strain differences in O3 susceptibility may be due to differences in O3 dose to the lung, which may be related to differences in the ability of the mice to lower their Tco in response to O3 exposure.

scholarly journals Body Temperature Changes during Transurethral Prostatectomy

1981 ◽  
Vol 9 (1) ◽  
pp. 43-46 ◽  
Author(s):  
R. E. Rawstron ◽  
J. K. Walton
Keyword(s):  
Body Temperature ◽  
Prospective Trial ◽  
Test Group ◽  
Control Group ◽  
Transurethral Prostatectomy ◽  
Temperature Changes ◽  
Significant Fall ◽  
Mean Temperature ◽  
Group A ◽  
Group B

A prospective trial was made to investigate the effects of cold irrigating solutions on body temperatures during transurethral resection of the prostate. In a control group of 45 cases, when the irrigating fluids had a mean temperature of 21.9°C, there was a significant fall in body temperature from 36 ± 0.6°C to 34.9 ± 0.7°C. In test group A of 48 cases, when the irrigating fluids had a mean temperature of 4.96°C, there was a significant fall in body temperature from 36.1 ± 0.6°C to 34.8 ± 0.9°C. In test group B (five cases) when the irrigating fluids had a mean temperature of 10.2 °C there was a significant fall in body temperature from 36.0 ± 0.4 to 34.6 ± 0.8. Comparative analyses between the control group and test group A did not show significant differences in the degrees of cooling in the two groups.

Discrimination, Temperature, and Time of Day

1979 ◽  
Vol 21 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Angus Craig
Keyword(s):  
Decision Making ◽  
Body Temperature ◽  
Signal Detection ◽  
Response Bias ◽  
Performance Measures ◽  
Signal Detection Theory ◽  
Discrimination Task ◽  
Time Of Day ◽  
Theory Approach ◽  
Oral Temperature

Performance measures on a binary discrimination task and oral temperature readings, were obtained at two times of day, morning (0800) and evening (2000), from each of 18 subjects. On the task, subjects reported not only the presence of signal A or B, but also the confidence of their judgment. A signal detection theory approach was applied to derive separate measures of perceptual efficiency and of the decision-making aspects. The results indicate that whereas efficiency, indexed by d', did not alter significantly between testing times, both response-bias and report confidence did change significantly, the latter showing an increase between morning and evening. A parallel rise in oral temperature was also found, and significant correlations between temperature and confidence were obtained. Neither efficiency nor response-bias was significantly related to temperature. The results are discussed in relation to previous reports that perceptual efficiency and body temperature are related and change in parallel during the normal waking day.

scholarly journals Decreasing human body temperature in the United States since the Industrial Revolution

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Myroslava Protsiv ◽  
Catherine Ley ◽  
Joanna Lankester ◽  
Trevor Hastie ◽  
Julie Parsonnet
Keyword(s):  
Body Temperature ◽  
Industrial Revolution ◽  
The United States ◽  
Time Of Day ◽  
Union Army ◽  
Oral Temperature ◽  
Mean Body Temperature ◽  
Health And Nutrition ◽  
The Us ◽  
Human Body Temperature

In the US, the normal, oral temperature of adults is, on average, lower than the canonical 37°C established in the 19th century. We postulated that body temperature has decreased over time. Using measurements from three cohorts—the Union Army Veterans of the Civil War (N = 23,710; measurement years 1860–1940), the National Health and Nutrition Examination Survey I (N = 15,301; 1971–1975), and the Stanford Translational Research Integrated Database Environment (N = 150,280; 2007–2017)—we determined that mean body temperature in men and women, after adjusting for age, height, weight and, in some models date and time of day, has decreased monotonically by 0.03°C per birth decade. A similar decline within the Union Army cohort as between cohorts, makes measurement error an unlikely explanation. This substantive and continuing shift in body temperature—a marker for metabolic rate—provides a framework for understanding changes in human health and longevity over 157 years.

Core body temperature changes after sauna exposition in healthy subjects

2012 ◽  
Vol 26 (2) ◽  
Author(s):  
Joanna Pawlak ◽  
Paweł Zalewski ◽  
Jacek J. Klawe ◽  
Monika Zawadka ◽  
Anna Bitner ◽  
...  
Keyword(s):  
Body Temperature ◽  
Healthy Subjects ◽  
Core Body Temperature ◽  
Temperature Changes ◽  
Core Body

scholarly journals Using body temperature and variables commonly available in the EHR to predict acute infection: a proof-of-concept study showing improved pretest probability estimates for acute COVID-19 infection among discharged emergency department patients

Diagnosis ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Carl T. Berdahl ◽  
An T. Nguyen ◽  
Marcio A. Diniz ◽  
Andrew J. Henreid ◽  
Teryl K. Nuckols ◽  
...  
Keyword(s):  
Emergency Department ◽  
Body Temperature ◽  
Acute Infection ◽  
Time Of Day ◽  
Pretest Probability ◽  
Absolute Difference ◽  
Proof Of Concept ◽  
Easy Method ◽  
Concept Study ◽  
Probability Estimates

Abstract Objectives Obtaining body temperature is a quick and easy method to screen for acute infection such as COVID-19. Currently, the predictive value of body temperature for acute infection is inhibited by failure to account for other readily available variables that affect temperature values. In this proof-of-concept study, we sought to improve COVID-19 pretest probability estimation by incorporating covariates known to be associated with body temperature, including patient age, sex, comorbidities, month, and time of day. Methods For patients discharged from an academic hospital emergency department after testing for COVID-19 in March and April of 2020, we abstracted clinical data. We reviewed physician documentation to retrospectively generate estimates of pretest probability for COVID-19. Using patients’ COVID-19 PCR test results as a gold standard, we compared AUCs of logistic regression models predicting COVID-19 positivity that used: (1) body temperature alone; (2) body temperature and pretest probability; (3) body temperature, pretest probability, and body temperature-relevant covariates. Calibration plots and bootstrap validation were used to assess predictive performance for model #3. Results Data from 117 patients were included. The models’ AUCs were: (1) 0.69 (2) 0.72, and (3) 0.76, respectively. The absolute difference in AUC was 0.029 (95% CI −0.057 to 0.114, p=0.25) between model 2 and 1 and 0.038 (95% CI −0.021 to 0.097, p=0.10) between model 3 and 2. Conclusions By incorporating covariates known to affect body temperature, we demonstrated improved pretest probability estimates of acute COVID-19 infection. Future work should be undertaken to further develop and validate our model in a larger, multi-institutional sample.

Ambient temperature effects on physiological traits of white-tailed deer

1975 ◽  
Vol 53 (6) ◽  
pp. 679-685 ◽  
Author(s):  
J. B. Holter ◽  
W. E. Urban Jr. ◽  
H. H. Hayes ◽  
H. Silver ◽  
H. R. Skutt
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Energy Expenditure ◽  
Ambient Temperature ◽  
Temperature Effects ◽  
Temperature Changes ◽  
Wind Chill ◽  
Ambient Temperatures ◽  
Energy Equilibrium ◽  
Body Energy

Six adult white-tailed deer (Odocoileus virginianus borealis) were exposed to 165 periods of 12 consecutive hours of controlled constant ambient temperature in an indirect respiration calorimeter. Temperatures among periods varied from 38 to 0 (summer) or to −20C (fall, winter, spring). Traits measured were energy expenditure (metabolic rate), proportion of time spent standing, heart rate, and body temperature, the latter two using telemetry. The deer used body posture extensively as a means of maintaining body energy equilibrium. Energy expenditure was increased at low ambient temperature to combat cold and to maintain relatively constant body temperature. Changes in heart rate paralleled changes in energy expenditure. In a limited number of comparisons, slight wind chill was combatted through behavioral means with no effect on energy expenditure. The reaction of deer to varying ambient temperatures was not the same in all seasons of the year.

On the Regulation of the Respiration in Reptiles

1961 ◽  
Vol 38 (2) ◽  
pp. 301-314 ◽  
Author(s):  
BODIL NIELSEN
Keyword(s):  
Steady State ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Temperature Interval ◽  
Normal Values ◽  
Pulmonary Ventilation ◽  
The Body ◽  
Respiratory Frequency ◽  
Temperature Changes ◽  
Instantaneous Increase

1. In two species of Lacerta (L. viridis and L. sicula) the effects on respiration of body temperature (changes in metabolic rate) and of CO2 added to the inspired air were studied. 2. Pulmonary ventilation increases when body temperature increases. The increase is brought about by an increase in respiratory frequency. No relationship is found between respiratory depth and temperature. 3. The rise in ventilation is provoked by the needs of metabolism and is not established for temperature regulating purposes (in the temperature interval 10°-35°C). 4. The ventilation per litre O2 consumed has a high numerical value (about 75, compared to about 20 in man). It varies with the body temperature and demonstrates that the inspired air is better utilized at the higher temperatures. 5. Pulmonary ventilation increases with increasing CO2 percentages in the inspired air between o and 3%. At further increases in the CO2 percentage (3-13.5%) it decreases again. 6. At each CO2 percentage the pulmonary ventilation reaches a steady state after some time (10-60 min.) and is then unchanged over prolonged periods (1 hr.). 7. The respiratory frequency in the steady state decreases with increasing CO2 percentages. The respiratory depth in the steady state increases with increasing CO2 percentages. This effect of CO2 breathing is not influenced by a change in body temperature from 20° to 30°C. 8. Respiration is periodically inhibited by CO2 percentages above 4%. This inhibition, causing a Cheyne-Stokes-like respiration, ceases after a certain time, proportional to the CO2 percentage (1 hr. at 8-13% CO2), and respiration becomes regular (steady state). Shift to room air breathing causes an instantaneous increase in frequency to well above the normal value followed by a gradual decrease to normal values. 9. The nature of the CO2 effect on respiratory frequency and respiratory depth is discussed, considering both chemoreceptor and humoral mechanisms.

TEMPERATURE REGULATION IN EXERCISE

PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 691-702
Author(s):  
Sid Robinson
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Heat Stroke ◽  
The Body ◽  
Physiological Regulation ◽  
Temperature Changes ◽  
Metabolic Heat ◽  
Warm Blood ◽  
Hot Environments ◽  
Large Increments

The central body temperature of a man rises gradually during the first half hour of a period of work to a higher level and this level is precisely maintained until the work is stopped; body temperature then slowly declines to the usual resting level. During prolonged work the temperature regulatory center in the hypothalamus appears to be reset at a level which is proportional to the intensity of the work and this setting is independent of environmental temperature changes ranging from cold to moderately warm. In hot environments the resistance to heat loss may be so great that all of the increased metabolic heat of work cannot be dissipated and the man's central temperature will rise above the thermostatic setting. If this condition of imbalance is continued long enough heat stroke will ensue. We have found that in a 3 mile race lasting only 14 minutes on a hot summer day a runner's rectal temperature may rise to 41.1°C., with heat stroke imminent. The physiological regulation of body temperature of men in warm environments and during the increased metabolic heat production of work is dependent on sweating to provide evaporative cooling of the skin, and on adjustments of cutaneous blood flow which determine the conductance of heat from the deeper tissues to the skin. The mechanisms of regulating these responses during work are complex and not entirely understood. Recent experiments carried out in this laboratory indicate that during work, sweating may be regulated by reflexes originating from thermal receptors in the veins draining warm blood from the muscles, summated with reflexes from the cutaneous thermal receptors, both acting through the hypothalamic center, the activity of which is increased in proportion to its own temperature. At the beginning of work the demand for blood flow to the muscles results in reflex vasoconstriction in the skin. As the body temperature rises the thermal demand predominates and the cutaneous vessels dilate, increasing heat conductance to the skin. Large increments in cardiac output and compensatory vasoconstriction in the abdominal viscera make these vascular adjustments in work possible without circulatory embarrassment.

scholarly journals VI.—The Body-Temperature of Fishes and other Marine Animals.

1908 ◽  
Vol 28 ◽  
pp. 66-84 ◽  
Author(s):  
Sutherland Simpson
Keyword(s):  
Body Temperature ◽  
Temperature Difference ◽  
Great Majority ◽  
The Body ◽  
Shore Crab ◽  
First Year ◽  
Marine Animals ◽  
Mean Temperature ◽  
The Mean ◽  
Image Position

SUMMARYThe body-temperature of the following fishes, crustaceans, and echinoderms has been examined and compared with the temperature of the water in which they live:—Cod-fish (Gadus morrhua), ling (Molva vulgaris), torsk (Brosmius brosme), coal-fish or saithe (Gadus virens), haddock (Gadus œgelfinus), flounder (Pleuronectes flesus), smelt (Osmerus eperlanus), dog-fish (Scyllium catulus), shore crab (Carcinus mœnas), edible crab (Cancer pagurus), lobster (Homarus vulgaris), sea-urchin (Echinus esculentus), and starfish (Asterias rubens). The minimum, maximum, and mean temperature difference for each species are given in the following table:—The excess of temperature is most evident in the larger specimens. This is well shown in the case of the coal-fish, where in the adult it was 0°·7 C., and in the great majority (11 out of 12) of the young of the first year, 0°·0 C. The body-weight and the conditions under which the fish are captured probably form the most important factors in determining the temperature difference.In 14 codfish, where the rectal, blood, and muscle temperatures were recorded in the same individual, it was found to be highest in the muscle and lowest in the rectum, the mean temperature difference being 0°·46 C. for the muscle, 0°·41 C for the blood, and 0°·36 C. for the rectum.

Sign in / Sign up

Export Citation Format

Share Document