Thermophysiological and Perceptual Responses of Amateur Healthcare Workers: Impacts of Ambient Condition, Inner-Garment Insulation and Personal Cooling Strategy.

While personal protective equipment (PPE) protects healthcare workers from viruses, it also increases the risk of heat stress. In this study, the effects of environmental heat stress, the insulation of the PPE inner-garment layer, and the personal cooling strategy on the physiological and perceptual responses of PPE-clad young college students were evaluated. Three levels of wet bulb globe temperatures (WBGT = 15 °C, 28 °C, and 32 °C) and two types of inner garments (0.37 clo and 0.75 clo) were chosen for this study. In an uncompensable heat stress environment (WBGT = 32 °C), the effects of two commercially available personal cooling systems, including a ventilation cooling system (VCS) and an ice pack cooling system (ICS) on the heat strain mitigation of PPE-clad participants were also assessed. At WBGT = 15 °C with 0.75 clo inner garments, mean skin temperatures were stabilized at 31.2 °C, Hskin was 60-65%, and HR was about 75.5 bpm, indicating that the working scenario was on the cooler side. At WBGT = 28 °C, Tskin plateaued at approximately 34.7 °C, and the participants reported "hot" thermal sensations. The insulation reduction in inner garments from 0.75 clo to 0.37 clo did not significantly improve the physiological thermal comfort of the participants. At WBGT = 32 °C, Tskin was maintained at 35.2-35.7 °C, Hskin was nearly 90% RH, Tcore exceeded 37.1 °C, and the mean HR was 91.9 bpm. These conditions indicated that such a working scenario was uncompensable, and personal cooling to mitigate heat stress was required. Relative to that in NCS (no cooling), the mean skin temperatures in ICS and VCS were reduced by 0.61 °C and 0.22 °C, respectively, and the heart rates were decreased by 10.7 and 8.5 bpm, respectively. Perceptual responses in ICS and VCS improved significantly throughout the entire field trials, with VCS outperforming ICS in the individual cooling effect.

Heat acclimation does not attenuate hepcidin elevation after a single session of endurance exercise under hot condition.

PURPOSE: We sought to determine the effects of heat acclimation on endurance exercise-induced hepcidin elevation under hot conditions. METHODS: Fifteen healthy men were divided into two groups: endurance training under hot conditions (HOT, 35 °C, n = 8) and endurance training under cool conditions (CON, 18 °C, n = 7). All subjects completed 10 days of endurance training (8 sessions in total), consisting of 60 min of continuous exercise at 50% of maximal oxygen uptake ([Formula: see text]) under their assigned environment condition. Subjects completed a heat stress exercise test (HST, 60 min exercise at 60% [Formula: see text]) to evaluate the exercise-induced thermoregulatory and hepcidin responses under hot conditions (35 °C) before (pre-HST) and after (post-HST) the training period. RESULTS: Core temperature during exercise in the post-HST decreased significantly in the HOT group compared to pre-HST (P = 0.004), but not in the CON group. The HOT and CON groups showed augmented exercise-induced plasma interleukin-6 (IL-6) elevation in the pre-HST (P = 0.002). Both groups had significantly attenuated increases in exercise-induced IL-6 in the post-HST; however, the reduction of exercise-induced IL-6 elevation was not different significantly between both groups. Serum hepcidin concentrations increased significantly in the pre-HST and post-HST in both groups (P = 0.001), no significant difference was observed between both groups during each test or over the study period. CONCLUSION: 10 days of endurance training period under hot conditions improved thermoregulation, whereas exercise-induced hepcidin elevation under hot conditions was not attenuated following the training.

Exoskeletons and Exosuits Could Benefit from Mode-Switching Body Interfaces That Loosen/Tighten to Improve Thermal Comfort.

Exoskeletons and exosuits (exos) are wearable devices that physically assist movement. User comfort is critically important for societal adoption of exos. Thermal comfort (a person's satisfaction with their thermal environment) represents a key design challenge. Exos must physically attach/interface to the body to apply forces, and these interfaces inevitably trap some heat. It is envisioned that thermal comfort could be improved by designing mode-switching exo interfaces that temporarily loosen around a body segment when assistive forces are not being applied. To inform exo design, a case series study (N = 4) based on single-subject design principles was performed. Our objective was to assess individual responses to skin temperature and thermal comfort during physical activity with a Loose leg-sleeve interface compared with a Form-Fitting one, and immediately after a Form-Fitting sleeve switched to Loose. Skin under the Loose sleeve was 2-3 °C (4-6 °F) cooler after 25 min of physical activity, and two of four participants reported the Loose sleeve improved their thermal comfort. After completion of the physical activity, the Form-Fitting sleeve was loosened, causing a 2-4 °C (3-8 °F) drop in skin temperature underneath for all participants, and two participants to report slightly improved thermal comfort. These findings confirmed that an exo that can quickly loosen its interface when assistance is not required-and re-tighten when it is- has the potential to enhance thermal comfort for some individuals and environments. More broadly, this study demonstrates that mode-switching mechanisms in exos can do more than adjust physical assistance: they can also exploit thermodynamics and facilitate thermoregulation in a way that enhances comfort for exo users.

Dynamics of temperature change during experimental respiratory virus challenge: Relationships with symptoms, stress hormones, and inflammation.

Thermoregulation is a complex, dynamic process involving coordination between multiple autonomic, endocrine, and behavioral mechanisms. In the context of infection, this intricate machinery generates fever, a process believed to serve vital functions in the body's defense against pathogens. In addition to increasing core temperature, infection can lead to changes in the dynamic fluctuations in body temperature over time. The patterns of these deviations may convey information about the health of the body and the course of illness. Here, we utilized dynamic structural equation modeling to explore patterns of body temperature change following an experimental respiratory virus challenge in an aggregated, archival dataset of human participants (N = 1,412). We also examined whether temperature dynamics during infection were related to symptom severity, as well as individual differences in biomarkers of inflammation and stress. We found that individuals meeting the criteria for infection exhibited higher but less stable body temperatures over time compared to those not meeting criteria of infection. While temperature parameters did not reliably predict symptom severity, higher levels of nasal proinflammatory cytokines were associated with lower, more consistent temperatures during the study period. Further, levels of salivary cortisol and urinary catecholamines measured at the beginning of the study appeared to have disparate effects on temperature change. In sum, this research highlights the utility of dynamic time series modeling as a framework for studying body temperature change and lends novel insights into how stress may interact with infection to influence patterns of thermoregulation.

Surgical masks do not increase the risk of heat stroke during mild exercise in hot and humid environment.

Surgical masks are widely used for the prevention of respiratory infections. However, the risk of heat stroke during intense work or exercise in hot and humid environment is a concern. This study aimed to examine whether wearing a surgical mask increases the risk of heat stroke during mild exercise in such environment. Twelve participants conducted treadmill exercise for 30 min at 6 km/h, with 5% slope, 35°C ambient temperature, and 65% relative humidity, while wearing or not a surgical mask (mask and control trials, respectively). Rectal temperature (Trec), ear canal temperature (Tear), and mean skin temperature (mean Tskin) were assessed. Skin temperature and humidity of the perioral area of the face (Tface and RHface) were also estimated. Thermal sensation and discomfort, sensation of humidity, fatigue, and thirst were rated using the visual analogue scale. Trec, Tear, mean Tskin, and Tface increased during the exercise, without any difference between the two trials. RHface during the exercise was greater in the mask trial. Hot sensation was greater in the mask trial, but no influence on fatigue and thirst was found. These results suggest that wearing a surgical mask does not increase the risk of heat stroke during mild exercise in moist heat.

Effects of Face Mask Use on Objective and Subjective Measures of Thermoregulation During Exercise in the Heat.

BACKGROUND: While increased face mask use has helped reduce COVID-19 transmission, there have been concerns about its influence on thermoregulation during exercise in the heat, but consistent, evidence-based recommendations are lacking. HYPOTHESIS: No physiological differences would exist during low-to-moderate exercise intensity in the heat between trials with and without face masks, but perceptual sensations could vary. STUDY DESIGN: Crossover study. LEVEL OF EVIDENCE: Level 2. METHODS: Twelve physically active participants (8 male, 4 female; age = 24 ± 3 years) completed 4 face mask trials and 1 control trial (no mask) in the heat (32.3°C ± 0.04°C; 54.4% ± 0.7% relative humidity [RH]). The protocol was 60 minutes of walking and jogging between 35% and 60% of relative VO2max. Rectal temperature (Trec), heart rate (HR), temperature and humidity inside and outside of the face mask (Tmicro_in, Tmicro_out, RHmicro_in, RHmicro_out) and perceptual variables (rating of perceived exertion (RPE), thermal sensation, thirst sensation, fatigue level, and overall breathing discomfort) were monitored throughout all trials. RESULTS: Mean Trec and HR increased at 30- and 60-minute time points compared with 0-minute time points, but no difference existed between face mask trials and control trials (P > 0.05). Mean Tmicro_in, RHmicro_in, and humidity difference inside and outside of the face mask (ΔRHmicro) were significantly different between face mask trials (P < 0.05). There was no significant difference in perceptual variables between face mask trials and control trials (P > 0.05), except overall breathing discomfort (P < 0.01). Higher RHmicro_in, RPE, and thermal sensation significantly predicted higher overall breathing discomfort (r2 = 0.418; P < 0.01). CONCLUSION: Face mask use during 60 minutes of low-to-moderate exercise intensity in the heat did not significantly affect Trec or HR. Although face mask use may affect overall breathing discomfort due to the changes in the face mask microenvironment, face mask use itself did not cause an increase in whole body thermal stress. CLINICAL RELEVANCE: Face mask use is feasible and safe during exercise in the heat, at low-to-moderate exercise intensities, for physically active, healthy individuals.

A Numerical Analysis of the Cooling Performance of a Hybrid Personal Cooling System (HPCS): Effects of Ambient Temperature and Relative Humidity.

Hybrid personal cooling systems (HPCS) incorporated with ventilation fans and phase change materials (PCMs) have shown its superior capability for mitigating workers' heat strain while performing heavy labor work in hot environments. In a previous study, the effects of thermal resistance of insulation pads, and latent heat and melting temperature of PCMs on the HPCS's thermal performance have been investigated. In addition to the aforementioned factors, environmental conditions, i.e., ambient temperature and relative humidity, also significantly affect the thermal performance of the HPCS. In this paper, a numerical parametric study was performed to investigate the effects of the environmental temperature and relative humidity (RH) on the thermal management of the HPCS. Five levels of air temperature under RH = 50% (i.e., 32, 34, 36, 38 and 40 °C) and four levels of environmental RH at two ambient temperatures of 36 and 40 °C were selected (i.e., RH = 30, 50, 70 and 90%) for the numerical analysis. Results show that high environmental temperatures could accelerate the PCM melting process and thereby weaken the cooling performance of HPCS. In the moderately hot environment (36 °C), HPCS presented good cooling performance with the maximum core temperature at around 37.5 °C during excise when the ambient RH ≤ 70%, whereas good cooling performance could be only seen under RH ≤ 50% in the extremely hot environment (40 °C). Thus, it may be concluded that the maximum environmental RH under which the HPCS exhibiting good cooling performance decreases with an increase in the environmental temperature.

Environmental neurology in the tropics.

We address the impact of the tropical environment on the human nervous system using the multifaceted approach characteristic of environmental neurology. First, environmental factors are examined according to their nature (physical, chemical and biological) and in relation to human activity and behavior. Some factors are specific to the tropics (climate and infections), while others are non-specific (chemicals, human communities and their way of life). Second, we examine the major role of human adaptation to the success of Homo sapiens, with emphasis on the linkage between thermoregulation and sleep-wake regulation. Third, we examine the performance of environmental neurology as a clinical discipline in tropical climates, with focus on the diagnostic and therapeutic challenges posed by human African trypanosomiasis. Finally, the prevention, early detection and monitoring of environmental neurological diseases is examined, as well as links with political and economic factors. In conclusion, practitioners of environmental neurology seek a global, multidisciplinary and holistic approach to understanding, preventing and treating neurological disorders within their purview. Environmental neurology integrates an expanded One Health concept by linking health and wellness to the interaction of plants, animals, humans and the ecosystem. Recent epidemics and the current COVID-19 pandemic exemplify the need for worldwide action to protect human health and biodiversity.

Personal protective equipment and personal cooling garments to reduce heat-related stress and injuries.

Use of appropriate personal protective equipment is essential for healthcare workers when dealing with patients who have tested positive or are suspected of having Covid-19. Personal protective equipment is uncomfortable at best. In hot countries (like India) or in a hot place of work, its wearers are at a high risk of heat-related illnesses. Once in personal protective equipment a healthcare worker can remain in it for at least 6 h at a stretch. In summer when it is hot and humid, personal protective equipment can cause wearer dehydration, heat exhaustion or heat fatigue. In a severe form, this can result in heat stroke and a collapse while on duty. Preventive measures are needed to protect healthcare workers. This review aims to highlight the efficacy and applicability of personal cooling garments.

[Recommendations about the Use of Psychotropic Medications during the COVID-19 Pandemic]. / Recomendações sobre a Utilização de Fármacos Psicotrópicos durante a Pandemia COVID-19.

INTRODUCTION: The COVID-19 pandemic is a particularly relevant threat to mentally ill patients, and it constitutes a new challenge for health care providers. To the best of our knowledge, there is not any embracing published review about the use of psychotropic drugs during the COVID-19 pandemic. MATERIALS AND METHODS: Non-systematic literature review. A search in the PubMed database was performed, with the terms 'psychotropic drugs', 'COVID-19', 'psychiatry' and 'pandemic'. Consensus and clinical guidelines about psychotropic drugs and COVID-19 approach, published by scientific societies, governmental entities and drug regulatory agencies were included. RESULTS AND DISCUSSION: We present the recommendations about the use of psychotropic drugs during the COVID-19 pandemic, in the outpatient and inpatient settings. The treatment of affective bipolar disorder and schizophrenia have now added increased difficulties. Some psychotropic drugs interfere with the pathophysiology of the novel coronavirus infection and they could interact with the drugs used in the treatment of COVID-19. Some patients will need pharmacological interventions due to the presence of delirium. Smoking cessation changes the serum levels of some psychotropic drugs and may influence their use. CONCLUSION: The COVID-19 pandemic has created new challenges in clinical practice. Psychiatric patients are a vulnerable population and often a careful clinical, laboratorial and electrocardiographic evaluation may be needed, particularly in those diagnosed with COVID-19. The regular treatment of mentally ill patients with COVID-19 presents increased complexity.

Introdução: A pandemia de COVID-19 constitui uma ameaça particularmente relevante para os portadores de doença mental e um novo desafio para os profissionais que os acompanham. Até à data, tanto quanto sabemos, não existe qualquer revisão abrangente publicada relativamente à utilização de fármacos psicotrópicos durante a pandemia COVID-19. Material e Métodos: Revisão não sistemática da literatura. A pesquisa na PubMed foi realizada com os termos 'psychotropic drugs', 'COVID-19', 'psychiatry' e 'pandemic'. Foram incluídos os consensos e as normas publicadas pelas sociedades científicas, entidades governamentais e agências regulamentares de medicamentos. Resultados e Discussão: Apresentam-se recomendações relativamente à utilização de psicofármacos durante a pandemia COVID-19, em contexto de ambulatório e de internamento. O tratamento da perturbação afetiva bipolar e da esquizofrenia tem agora dificuldades acrescidas. Alguns psicofármacos interferem com os mecanismos fisiopatológicos envolvidos na infeção pelo novo coronavírus e têm interações com os fármacos utilizados no tratamento da COVID-19. Em doentes com COVID-19 e com delirium, a utilização de psicofármacos poderá ser necessária. A cessação tabágica altera os níveis séricos de alguns psicofármacos e pode condicionar a sua utilização. Conclusão: A pandemia de COVID-19 coloca novos desafios na prática clínica. Os doentes psiquiátricos constituem uma população vulnerável, sendo frequentemente necessária uma avaliação clínica, laboratorial e eletrocardiográfica cuidadosa, naqueles com o diagnóstico de COVID-19. Os doentes mentais com COVID-19 apresentam uma complexidade acrescida na gestão da sua terapêutica habitual.