scholarly journals Cooling Interventions Among Agricultural Workers: A Pilot Study

2020 ◽  
pp. 216507992097652
Author(s):  
Roxana Chicas ◽  
Nezahualcoyotl Xiuhtecutli ◽  
Lisa Elon ◽  
Madeleine K. Scammell ◽  
Kyle Steenland ◽  
...  
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
The United States ◽  
Agricultural Workers ◽  
Control Group ◽  
Temperature Threshold ◽  
Convenience Sample ◽  
Ambient Temperatures ◽  
Core Body

Background Adverse health effects among agricultural workers due to chronic heat exposure have been characterized in the literature as not only due to high ambient temperatures but also due to intensive manual labor in hot and humid conditions. The aim of this study was to use biomonitoring equipment to examine the effectiveness of selected cooling devices at preventing agricultural workers from exceeding the core body temperature threshold of 38.0°C (Tc38) and attenuating heat-related illness symptoms. Methods A convenience sample of 84 agricultural workers in Florida was randomized to one of four groups: (a) no intervention, clothing as usual; (b) cooling bandana; (c) cooling vest; and (d) both the cooling bandana and cooling vest. Biomonitoring equipment worn by the participants included core body temperature monitor and an accelerometer to capture physical activity. Findings A total of 78 agricultural workers completed one intervention workday trial. Compared with the control group, the bandana group had lower odds of exceeding Tc38 (odds ratio [OR] = 0.7, 90% confidence interval [CI] = [0.2, 3.2]) and the vest group had higher odds of exceeding Tc38 (OR = 1.8, 90% CI = [0.4, 7.9]). The simultaneous use of cooling vest and bandana showed an effect little different from the control group (OR = 1.3, 90% CI = [0.3, 5.6]). Conclusion/Application to Practice This is the first field-based study to examine cooling intervention among agricultural workers in the United States using biomonitoring equipment. This study found that using a bandana while working in a hot agricultural environment has the potential to be protective against exceeding the recommended Tc38 threshold.

scholarly journals A novel mouse model of heatstroke accounting for ambient temperature and relative humidity

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuyuki Miyamoto ◽  
Keisuke Suzuki ◽  
Hirokazu Ohtaki ◽  
Motoyasu Nakamura ◽  
Hiroki Yamaga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Organ Damage ◽  
Core Body ◽  
The Impact ◽  
Treatment Water

Abstract Background Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure. Methods Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS. Results The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage. Conclusions We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.

scholarly journals Effects of Pre-cooling and Per-cooling on Neural, Physiological, and Functional Responses in Active Young Girls

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Seyedeh Somayeh Razavi ◽  
Amirabbas Monazzami ◽  
Zahra Nikosefat
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Temperature ◽  
Repeated Measures ◽  
Blood Pressure Monitoring ◽  
Core Body Temperature ◽  
Control Group ◽  
Functional Responses ◽  
Young Girls ◽  
Core Body

Background: Stressful environments, especially air temperature, have significant effects on human physiological responses to physical activity. Objectives: The current study aimed to determine the effects of pre-cooling and per-cooling on neural, physiological, and functional responses in active young girls. Methods: Twelve active girls (age 24.6 ± 1.4, weight 55.46 ± 8.18, height 165.1 ± 5.91) were tested in three separate sessions with intervals of three days between each session. All subjects performed the Balke test in three groups either without an ice vest (control and pre-cooling) or with an ice vest (per-cooling) in each session, randomly. Pre-cooling was applied with an ice vest for 30 min just before the test, while per-cooling was used with an ice vest from the beginning of the test to exhaustion. A Buerer FT-70 digital thermometer, polar-FT60 heart rate monitoring, Microlife blood pressure monitoring, and ELISA technique were used to measure core body temperature, heart rate, blood pressure, dopamine, cortisol, and lactate dehydrogenase, respectively. Two-way repeated-measures ANOVA was applied to analyze the data with a confidence interval of 95%. Results: The heart rate and core body temperature significantly decreased at the end of the test in the pre-cooling and per-cooling groups (P < 0.05). There was an improved performance with an increase in Tmax in the per-cooling group compared to the control group (P < 0.05) although this difference was not significant in the pre-cooling group compared to the control group (P > 0.05). Dopamine, cortisol, and lactate dehydrogenize increased in the groups in comparison with the pretest (P < 0.05) even though these differences were not significant in the comparison between the groups (P > 0.05). Conclusion: The findings suggest that pre-cooling and per-cooling could be used as a beneficial method to improve performance due to not only a decrease in core body temperature and heart rate but also an increase in the level of dopamine and cortisol. Moreover, per-cooling was more effective than pre-cooling to increase performance.

scholarly journals Novel Analytic Methods Needed for Real-Time Continuous Core Body Temperature Data

2016 ◽  
Vol 39 (1) ◽  
pp. 95-111 ◽  
Author(s):  
Vicki Hertzberg ◽  
Valerie Mac ◽  
Lisa Elon ◽  
Nathan Mutic ◽  
Abby Mutic ◽  
...  
Keyword(s):  
Data Analysis ◽  
Body Temperature ◽  
Real Time ◽  
Time Course ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Threshold Limit Value ◽  
Limit Value ◽  
Novel Approach ◽  
Core Body

Affordable measurement of core body temperature (Tc) in a continuous, real-time fashion is now possible. With this advance comes a new data analysis paradigm for occupational epidemiology. We characterize issues arising after obtaining Tc data over 188 workdays for 83 participating farmworkers, a population vulnerable to effects of rising temperatures due to climate change. We describe a novel approach to these data using smoothing and functional data analysis. This approach highlights different data aspects compared with describing Tc at a single time point or summaries of the time course into an indicator function (e.g., did Tc ever exceed 38 °C, the threshold limit value for occupational heat exposure). Participants working in ferneries had significantly higher Tc at some point during the workday compared with those working in nurseries, despite a shorter workday for fernery participants. Our results typify the challenges and opportunities in analyzing Big Data streams from real-time physiologic monitoring.

Role of the hypothalamic PVN in the reflex reduction in mesenteric blood flow elicited by hyperthermia

2008 ◽  
Vol 295 (6) ◽  
pp. R1874-R1881 ◽  
Author(s):  
Feng Chen ◽  
Melissa Dworak ◽  
Yuliang Wang ◽  
Joo Lee Cham ◽  
Emilio Badoer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Separate Group ◽  
Control Group ◽  
Mesenteric Blood Flow ◽  
Significant Difference ◽  
Core Body

The hypothalamic paraventricular nucleus (PVN) is an important integrative center in the brain. In the present study, we investigated whether the PVN is a key region in the mesenteric vasoconstriction that normally accompanies an increase in core body temperature. Anesthetized rats were monitored for blood pressure, heart rate, mesenteric blood flow, and vascular conductance. In control rats, elevation of core body temperature to 41°C had no significant effect on blood pressure, increased heart rate, and reduced mesenteric blood flow by 21%. In a separate group of rats, muscimol was microinjected bilaterally (1 nmol/side) into the PVN. Compared with the control group, there was no significant difference in the blood pressure and heart rate responses elicited by the increase in core body temperature. In contrast to control animals, however, mesenteric blood flow did not fall in the muscimol-treated rats in response to the elevation in core body temperature. In a separate group, in which muscimol was microinjected into regions outside the PVN, elevating core body temperature elicited the normal reduction in mesenteric blood flow. The results suggest that the PVN may play a key role in the reflex decrease in mesenteric blood flow elicited by hyperthermia.

The effects of heat stress on cognition in persons with multiple sclerosis

2011 ◽  
Vol 18 (4) ◽  
pp. 489-497 ◽  
Author(s):  
P Hämäläinen ◽  
A Ikonen ◽  
A Romberg ◽  
H Helenius ◽  
J Ruutiainen
Keyword(s):  
Multiple Sclerosis ◽  
Heat Stress ◽  
Body Temperature ◽  
Cognitive Functioning ◽  
Cognitive Deficits ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Heat Sensitivity ◽  
Serial Addition ◽  
Core Body

Background: Heat sensitivity and cognitive deficits are typical manifestations of multiple sclerosis (MS). Although cognitive deficits are quite well characterized, practically no data exist on the effects of heat on cognitive performances in MS. Objective: To assess the effects of short-term heat stress on cognitive functioning in subjects with MS. Methods: A total of 23 heat-sensitive MS and 19 healthy control (HC) subjects participated. Moderate heat exposure took place in a Finnish sauna. Cognitive functioning was measured with tests of sustained attention and processing speed, the Paced Auditory Serial Addition Test (PASAT 3” and 2”) and the computerized visual vigilance test, before, during and after heat exposure. Results: During the heat exposure, the core body temperature of the MS group rose significantly more ( p = 0.002) than that of the HC group. The heat stress worsened the performance of the MS group in the PASAT 3” ( p = 0.025) but not in the other cognitive measures. The performance in the PASAT 3” was reversed almost to the baseline level only 1- h after the heat exposure. Conclusions: A significant increase in core body temperature during heat stress is associated with a mild and reversible worsening of the PASAT 3” performance, while visual vigilance performance seems to remain almost unaffected.

scholarly journals Organic selenium effect on body temperature and body weight in broilers

2017 ◽  
Vol 1 (4) ◽  
pp. 332-336
Author(s):  
Adrian Răduță ◽  
Dumitru Curcă
Keyword(s):  
Body Weight ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Control Group ◽  
Feed Conversion ◽  
Organic Selenium ◽  
Average Temperature ◽  
Cholesterol Levels ◽  
Core Body ◽  
Experimental Group

Abstract The research was conducted on a group of 20 3-weeks-old chicken from the Cobb breed that were divided into two batches. Both batches received a 21/1 ratio feed diet for broiler chicken in their finishing period. The experimental group feed was supplemented with 0.5 ppm selenium, with 0.25 ALKOSEL R397 g/kg mixed fodder. 30 days into this feeding regime, the following determinations were made weekly: body weight, body temperature and computerized thermography of the comb and wattle. The obtained results were tabled and bio statistically analyzed revealing that individuals in the experimental batch showed statistically significant increases of the values for body weight (average body weight was 14.78% larger than that of the control batch) and of the temperature measured in the combs (average temperature was 12.97% higher) and wattles (average temperature was 4.12% higher). The experimental group also registered a higher core body temperature, but not statistically significant in comparison with the control group. Association of the higher values of core and peripheral body temperature with increased body weight in the individuals from the experimental group, correlated with an increased number of red blood cells and lower cholesterol levels suggest an improved basal metabolism and a better feed conversion.

scholarly journals Risk Factors for Reaching Core Body Temperature Thresholds in Florida Agricultural Workers

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Valerie Mac ◽  
Lisa Elon ◽  
Jacqueline Mix ◽  
Antonio Tovar-Aguilar ◽  
Joan Flocks ◽  
...  
Keyword(s):  
Risk Factors ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Agricultural Workers ◽  
Temperature Thresholds ◽  
Core Body

scholarly journals Combined stimuli of cold, hypoxia, and dehydration status on body temperature in rats: a pilot study with practical implications for humans

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Tadashi Uno ◽  
Tatsuya Hasegawa ◽  
Masahiro Horiuchi
Keyword(s):  
Body Temperature ◽  
Environmental Conditions ◽  
Multiple Stressors ◽  
Core Body Temperature ◽  
Area Under The Curve ◽  
Ambient Temperatures ◽  
Hypoxic Conditions ◽  
Loss Index ◽  
Core Body ◽  
Heat Loss Index

Abstract Objective As human thermoregulatory responses to maintain core body temperature (Tcore) under multiple stressors such as cold, hypoxia, and dehydration (e.g., exposure to high-altitude) are varied, the combined effects of cold, hypoxia, and dehydration status on Tcore in rats were investigated. The following environmental conditions were constructed: (1) thermoneutral (24 °C) or cold (10 °C), (2) normoxia (21% O2) or hypoxia (12% O2), and (3) euhydration or dehydration (48 h water deprivation), resulted in eight environmental conditions [2 ambient temperatures (Ta) × 2 oxygen levels × 2 hydration statuses)]. Each condition lasted for 24 h. Results Normoxic conditions irrespective of hypoxia or dehydration did not strongly decrease the area under the curve (AUC) in Tcore during the 24 period, whereas, hypoxic conditions caused greater decreases in the AUC in Tcore, which was accentuated with cold and dehydration (Ta × O2 × hydration, P = 0.040 by three-way ANOVA). In contrast, multiple stressors (Ta × O2 × hydration or Ta × O2 or O2 × hydration or Ta × hydration) did not affect locomotor activity counts (all P > 0.05), but a significant simple main effect for O2 and Ta was observed (P < 0.001). Heat loss index was not affected by all environmental conditions (all P > 0.05). In conclusion, decreases in Tcore were most affected by multiple environmental stressors such as cold, hypoxia, and dehydration.

Effects of 6-hydroxydopamine and pimozide on temperature maintenance by the chicken

1980 ◽  
Vol 239 (3) ◽  
pp. R296-R302
Author(s):  
D. L. Rowe-Murphy ◽  
A. van Tienhoven ◽  
N. R. Scott ◽  
P. E. Hillman ◽  
C. L. Wood ◽  
...  
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Control Treatment ◽  
Noradrenergic System ◽  
Ambient Temperatures ◽  
Drug Treatments ◽  
Lower Maximum ◽  
6 Hydroxydopamine ◽  
Core Body

Intraventricular implants of pimozide in adult white leghorn hens were used to block dopamine (DA) receptors, and 6-hydroxydopamine (6-OHDA) was injected intraventricularly to destroy the noradrenergic system locally. The hens were exposed to ambient temperatures of 5 and 35 degrees C, and their core temperature was measured. One hundred micrograms of 6-OHDA significantly reduced the norepinephrine (NE) but not the DA content of the hypothalamus and reduced the uptake of [3H]NE but not of [3H]DA by synaptosomes in vitro. Neither of the drug treatments nor their combination affected average core body temperature (Tb) at either 5 or 35 degrees C. Pimozide treatment caused a lower maximum Tb at 35 degrees C and a higher maximum Tb at 5 degrees C than the control treatment. No evidence was obtained that 6-OHDA treatment affected body temperature regulation. It is concluded that neither the DA nor the NE system is essential for normal temperature maintenance in the hen exposed to either 5 or 35 degrees C.

scholarly journals Heat Exposure and Physiological Changes among Cooks

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Siti Marwanis Anua ◽  
Mohd Nizamuddin Ismail ◽  
Mohd Amierul Aieman Mohd Nordin ◽  
Faridah Naim ◽  
Nurul Ainun Hamzah ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Sampling Site ◽  
Heat Exposure ◽  
Physiological Changes ◽  
Sweat Production ◽  
Core Body ◽  
Post Shift

Cooks who are exposed to heat produced from stoves when working in the kitchen are at risk of thermal stress and heat-related illness. Physiological changes such as increased heart rate, sweat production and blood pressure may also affect them. This study aimed to determine the area heat exposure levels and physiological changes including core body temperature, blood pressure and heart rate during pre-, mid- and post-shift among cooks and its association, and to compare the mean difference of physiological changes between the shifts. This cross-sectional study utilised the purposive sampling method and recruited 30 cooks from food stalls and cafeterias in Kelantan. Area heat measurements were collected from 14 sites (7 inside and 7 outside the USM Health Campus). Wet-bulb Globe Temperature (WBGT) monitor was mounted on a tripod at 1.1 m height near the source of heat for 8 hours. The core body temperature, blood pressure, and heart rate were taken three times per day during pre-, mid- and post-shift for physiological changes measurement. Respondents’ personal information, health history, work description, and symptoms of heat-related illness were collected using a questionnaire. The overall WBGT area levels at each sampling site were homogeneously distributed. There was significant increase in core body temperature and heart rate from pre-shift to post-shift. However, there was no significant correlation (p>0.05) between heat exposure (WBGT index) established with the physiological changes. This may suggest that the increase in core body temperature and heart rate might be attributed to other factors and needed further investigation.

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