Investigation of gender difference in human response to temperature step changes

doi:10.1016/j.physbeh.2015.07.037

Physiology & Behavior

Volume 151, 1 November 2015, Pages 426-440

https://doi.org/10.1016/j.physbeh.2015.07.037 Get rights and content

Highlights

•
Women lowered oral temperatures more intensively than men after up-step of S15.
•
Men witnessed a more remarkable decrease in RMSSD after up-step of S15 than women.
•
Men regulated skin temperatures more robustly and swiftly than women.
•
Women felt lower temperature cooler and higher temperature warmer than men.

Abstract

The purpose of this study was to examine gender difference in human response to temperature step changes. A total of three step-change conditions (S5: 32 °C–37 °C–32 °C, S11: 26 °C–37 °C–26 °C, and S15: 22 °C–37 °C–22 °C) were designed and a laboratory experiment with 12 males and 12 females was performed. Results of this study support our hypothesis that females differ from males in human response to sudden temperature changes from the perspectives of psychology, physiology and biomarkers. Females are more prone to show thermal dissatisfaction to cool environments while males are more likely to feel thermal discomfort in warm environments. It is logical that men have a stronger thermoregulation ability than women as male skin temperature change amplitude is smaller while the time to be stable for skin temperature is shorter than that of females after both up-steps and down-steps. In S15, males witnessed a more intensive decrease in RMSSD while females underwent a remarkable instant reduce in oral temperatures after the up-step. Marginal significance was observed in male IL-6 before and after the up-step in S15 while female IL-6 prominently increased after the down-step in S15.

Introduction

Human beings are often likely to expose themselves to sudden temperature changes in daily life. For example, people will encounter temperature steps when entering or exiting air-conditioned buildings and getting on or off planes. Many studies have been carried out to examine human subjective and objective responses to transient thermal environments. However, most of them did not consider gender difference as some studies only enrolled males in their experiments [1], [2], [3], [4], [5], [6], and some even did not give subjects' gender information [7], [8]. Moreover, although some dynamic thermal environment research did recruit both males and females as subjects [9], [10], [11], [12], only Chen discussed gender difference from the aspect of thermal sensation and skin physiology [12], followed by Zhai presenting a simple gender comparison in thermal sensation and dissatisfaction [13]. No circumstantial analysis on gender difference in human response to temperature step changes has been published.

As far as thermal perceptions are concerned, Karjalainen conducted a detailed review comprising chamber studies and field surveys, and gave a synopsis of thermal comfort experienced by men and women, which concluded that females were more likely than males to express thermal dissatisfaction; however, no significant gender difference was found in neutral temperatures in most studies; females are more sensitive than males to a deviation from an optimal temperature and express more dissatisfaction, especially in cooler conditions [14]. Nevertheless, as the review shows, most studies focus on human thermal comfort under steady environments rather than transient environments and could not reflect human dynamic response. In addition, objective measures like physiological parameters and biomarkers are applied more and more widely in thermal environment studies [15], [16], [17], [18], but few gender difference analyses were delivered and even much less studies on the bodily reaction to temperature steps between different gender groups were performed.

The purpose of this study was to investigate gender difference in human response to the alteration in thermal environment. We hypothesized that females are different from males in their responses to different temperature steps from the perspectives of psychology, physiology and biomarkers.

Section snippets

Subjects

Twenty four healthy undergraduate students (half males and half females) with an average age of 22 ± 1 years were recruited in the study. Preliminary evaluation of applicants was conducted to exclude those who might suffer cardiovascular disease, respiratory disease and skin disease which might interfere with the physiological and biochemical measures used in this experiment. Table 1 is the summary of their anthropometric information. Every subject's body mass index rates in the normal range [19].

Health symptoms

The change of self-reported symptoms over time in response to temperature steps for males and females is displayed in Fig. 3. In S5, when returning to 32 °C from 37 °C, fewer males reported the perspiration symptom and the percentage of males ended at about 10% while that of females was 50%. The chi-square test demonstrates significant gender difference at the end of phase 3 (P < 0.05). In general, the percentage of self-reported eyestrain for females is higher than that for males. Particularly,

Subjective perceptions

Our results show that significantly more females reported perspiration at the end of the down-step adaptive process of S5. One possible reason is that heat convection between males and the environment is more intensive than that of females because male skin temperature is lower than its female counterpart in S5. So, males may gain thermal balance just through heat convection while females may have to exert heat dissipation through convection and sweat evaporation. Women being more sensitive to

Conclusions

Gender difference in human response to the alteration in thermal environment was investigated from the aspect of psychology, physiology and biomarkers. It can be concluded that:

1.
When encountering the up-step in S15, both males and females significantly lowered their oral temperatures to protect the core part of the body. However, female instant change of oral temperature after the up-step in S15 is profoundly more intensive than that of males.
2.
It is logical that males have a stronger

Acknowledgments

This work is financially supported by Key Program of the National Natural Science Foundation of China (51238005).

References (35)

H. Liu et al.
The response of human thermal perception and skin temperature to step-change transient thermal environments
Build. Environ.
(2014)
C. Chun et al.
Thermal comfort in urban transitional spaces
Build. Environ.
(2005)
Y. Zhang et al.
Effects of step changes of temperature and humidity on human responses of people in hot-humid area of China
Build. Environ.
(2014)
C.Y. Chun et al.
Thermal environment and human responses in underground shopping malls vs department stores in Japan
Build. Environ.
(1998)
C.-P. Chen et al.
Effects of temperature steps on human skin physiology and thermal sensation response
Build. Environ.
(2011)
S. Qian et al.
Effects of short-term environmental hyperthermia on patterns of cerebral blood flow
Physiol. Behav.
(2014)
Y. Liu
Human behavior in different TDRAs
Physiol. Behav.
(2013)
Z.J. Schlader et al.
The independent roles of temperature and thermal perception in the control of human thermoregulatory behavior
Physiol. Behav.
(2011)
M.Y. Beshir et al.
Comparison between male and female subjective estimates of thermal effects and sensations
Appl. Ergon.
(1981)
W.L. Kenney
A review of comparative responses of men and women to heat stress
Environ. Res.
(1985)

P. Mehnert et al.

Gender-related difference in sweat loss and its impact on exposure limits to heat stress

Int. J. Ind. Ergon.

(2002)

J. Waugh et al.

Differences in capnography and pulse oximetry measurements related to gender

Chest

(2012)

M.D. Witting et al.

Diagnostic room-air pulse oximetry: effects of smoking, race, and sex

Am. J. Emerg. Med.

(2008)

J. Zhang

Effect of age and sex on heart rate variability in healthy subjects

J. Manip. Physiol. Ther.

(2007)

Gagge AP, Stolwijk J, Hardy J. Comfort and thermal sensations and associated physiological responses at various ambient...

R. Dear et al.

Thermal sensations resulting from sudden ambient temperature changes

Indoor Air

(1993)

K. Nagano et al.

Effects of ambient temperature steps on thermal comfort requirements

Int. J. Biometeorol.

(2005)

Cited by (60)

Experimental study on the physiological parameters of occupants under different temperatures and prediction of their thermal comfort using machine learning algorithms
2024, Journal of Building Engineering
Real-time prediction of indoor thermal comfort has great potential in the development of a thermal comfort-driven control method for heating, ventilation, and air conditioning (HVAC) systems and the improvement of the indoor environment. This study measured physiological parameters (including electrocardiogram (ECG) signal, electroencephalogram (EEG) signal, and skin temperature (ST)) of 10 male and 10 female volunteers under three temperature conditions (22 °C, 25 °C, and 28 °C). A setup database containing 3600 sets of data was used to develop the thermal comfort prediction model with three machine learning algorithms: random forest (RF), back-propagation neural network (BP), and convolutional neural network (CNN). Significant differences were found in both the values and the impact indices of physiological indicators between males and females (p < 0.05). The RF algorithm had a significant advantage with an overall accuracy of 89.3 %. If only one factor is employed for machine learning training, using the RF algorithm and training with the ST dataset is the most appropriate method, with an accuracy of 81.8 %. The addition of all datasets can increase the modeling accuracy to 95.6 %. Taking into account the sample imbalance, the SMOTETomek method was applied. After applying the SMOTETomek method to balance the data, the model accuracy reached at 97.3 %. The comprehensive results showed that thermal comfort prediction for the mixed group of males and females by the RF algorithm using one hybrid model was feasible. The establishment of this model laid the foundation for thermal comfort-driven HVAC control methods and the improvement of indoor environments.
Gender disparities in thermal responses under vertical air temperature differences
2024, Energy and Buildings
The effects of vertical temperature differences (VTD) on human thermal comfort have attracted growing attention from researchers when utilizing split air conditioners for winter heating. This study underscores the need to investigate the influences of gender disparities in the context of significant vertical temperature variations, a critical aspect that has not yet been comprehensively explored. Twenty gender-balanced subjects were exposed to a variety of stratified thermal environments created by a split air-conditioner. Their overall and local perceptual and physiological responses were measured at various operative temperatures and VTD. Results show that females have lower thermal sensation vote (TSV) and mean skin temperature under the same environments compared to males. Neutral operative temperatures of females and males are 23.7 ˚C and 20.8 ˚C, respectively. On the cold side, lower leg and foot thermal sensations are dominant whereas chest and back are dominant on the warm side. When females rated “slightly warm” (TSV equaled 1) or “warm” (TSV equaled 2), or males rated “slightly cool” (TSV equaled −1), increased VTD can lower thermal acceptability. The research findings have significant implications for the understanding of gender requirements of stratified heating environments and for maximizing the thermal comfort of the two genders.
Contact cooling for bare feet using floor cooling systems: Experiment on human thermal physiology and sensation in Japanese hot environment
2024, Building and Environment
This study clarifies the contact cooling effect of bare feet on human thermal physiology and sensation using a floor cooling system under hot environments. An experiment was conducted with 14 healthy young men and women using a water-cooled floor panel to investigate the cooling effects under Japanese summer conditions. The results revealed that the influences of the room temperature on the physiological parameters including blood flow, mean skin temperature, and sublingual temperature were more sensitive than that of the floor temperature. Nevertheless, the contact cooling of the soles with the floor temperature of 28 °C reduced the percentage of “very hot” and “hot” sensations of the entire body by 15.5 % when the room temperature was 30 °C. Moreover, the contact cooling of the soles at the room temperature of 30 °C increased heat flow from the soles while maintaining constant blood flow when the floor temperature was decreased. Thus, contact cooling of the soles was confirmed to be effective for heat mitigation in hot environments. However, the contact cooling was likely to cause thermal discomfort owing to the cold sensation as the room temperature decreased to 24 °C. Individual differences, in addition to the sex differences, occurred in the contact cooling effects on blood flow and skin temperature. Individual differences in blood flow were primarily caused by differences in basal metabolism and muscle mass. Further energy savings for space cooling and improved thermal comfort will be achieved by considering the individual differences for the floor cooling systems.
Experimental evaluation of ECG signal denoising methods based on HRV indices and their application in indoor thermal comfort study under different temperatures
2024, Energy and Buildings
The heart rate variability (HRV) features extracted from an electrocardiogram (ECG) signal have been widely used to help improve the performance of thermal comfort models, with the ECG signal denoising method being very important. In this study, 20 volunteers were recruited for experiments in a well-controlled chamber. Their ECG signals (a total of 6,000,000 sets of data) were collected under stable and variable temperature environments. With the use of the setup database, four denoising methods were compared: the fast Fourier transform (FFT), wavelet transform, Chebyshev filter, and Butterworth filter. When the performance of these methods was evaluated from ECG images, the Butterworth filter exhibited a more comprehensive and smoother representation of the original signal. Judging from denoising indices, the Butterworth filter exhibited the best performance, with its denoising indices surpassing those of fast Fourier transform and wavelet transform by differences ranging from 26% to 122%. Judging from HRV index and R-peak positioning, the data processed by Butterworth exhibited the highest reliability (93.5%), outperforming FFT (30.0%), the wavelet filter (72.5%), and the Chebyshev filter (78.5%). Furthermore, the 5th-order Butterworth filter exhibited the largest signal-to-noise ratio (SNR) with 1.1–34.4% larger and the smallest percent root-mean-square difference (PRD) with 15.2–66.1% smaller compared to other orders. Next, the characteristics of denoised HRV features under different temperatures were studied. During a temperature rise stage, the fitting R² values of rMSSD, SDNN, and HR with temperature were 0.85, 0.64, and 0.78, respectively; meanwhile, during the subsequent temperature drop stage, the fitting R² values were 0.78, 0.84, and 0.78, respectively. This suggests that changes in temperature can be effectively reflected by HRV indices. When gender was taken into consideration, the HR of females showed a 55.8% higher fitting level compared to males.
Performance of an innovative personalized ventilation mode based on air attachment under non-isothermal air supply conditions
2024, Energy and Buildings
In view of the shortcomings of traditional personalized ventilation method, an innovative mode of personalized ventilation was explored in this study. To investigate the performance of the personalized ventilation mode, velocity field measurements were performed to examine the impact of the supply air temperature on the airflow distributions, and a tracer gas system was used to test the fresh-air ratio in the breathing zone. The results show that the critical supply air velocity increases as a function of the supply air temperature and that the position height of the air attachment formation is a decreasing function of the supply air temperature. The fresh-air ratio in the breathing zone was significantly correlated with the formation and height of the attachment. Furthermore, the higher the position of the air attachment formation, the greater the breathable fresh-air ratio. The breathable fresh-air ratios were 83.3 %, 82.3 % and 84.1 % at supply air velocities of 0.3 m/s, 0.4 m/s and 0.5 m/s, respectively, and a supply air temperature of 17 °C. Compared with the traditional air supply method, the ventilation effectiveness of the the air dress personalized ventilation(ADPV) method in this study is highest. Irritation in the eyes was weaker than that in other areas. Irritation in the lips and nose was an increasing function of the supply air velocity, and no obvious connection with the supply air temperature. Furthermore, the supply air velocity and temperature significantly influenced the sensation in the upper body; however, no obvious influence was observed on the sensation in the lower body. It was verified that the ADPV method was able to satisfy the requirements of human comfort and the breathable air quality simultaneously.
Sex-based thermal comfort zones and energy savings in spaces with joint operation of air conditioner and fan
2023, Building and Environment
Fan and air conditioner combined systems (FACS) have been demonstrated as a viable alternative to conventional air conditioning systems, providing thermal comfort to occupants while consuming less energy. However, few studies have quantitatively established occupant comfort zones for FACS operation and analyzed its energy saving effects. An experiment was conducted first to develop thermal comfort zone in spaces with FACS operation. As the indoor temperature rises, the upper limit of air speed accepted by occupants increases. Females exhibit an upper comfort range parameter of 29.8 °C and 1.4 m/s, while males demonstrate 29.3 °C and 1.5 m/s. There are noticeable differences in comfort ranges between males and females, especially in cooler conditions. Based on the established comfort zone, energy simulation studies were conducted for most regions of China to investigate the potential energy savings resulting from the implementation of FACS in ASHRAE standard office building. Buildings incorporating FACS demonstrate a reduction in HVAC system energy consumption by more than 16 % when compared to indoor temperature set at 26 °C. In hot summer and warm winter climates, HVAC system energy savings of over 100 GJ/year can be achieved using FACS for the standard building. Considering sex differences in FACS operation leads to additional energy savings.

View all citing articles on Scopus

View full text

Investigation of gender difference in human response to temperature step changes

Highlights

Abstract

Introduction

Section snippets

Subjects

Health symptoms

Subjective perceptions

Conclusions

Acknowledgments

Build. Environ.

Build. Environ.

Build. Environ.

Build. Environ.

Build. Environ.

Physiol. Behav.

Physiol. Behav.

Physiol. Behav.

Appl. Ergon.

Environ. Res.

Int. J. Ind. Ergon.

Chest

Am. J. Emerg. Med.

J. Manip. Physiol. Ther.

Thermal sensations resulting from sudden ambient temperature changes

Indoor Air

Effects of ambient temperature steps on thermal comfort requirements

Int. J. Biometeorol.