Thermal discomfort in healthcare workers during the COVID-19 pandemic.

INTRODUCTION: Due to the COVID-19 pandemic, healthcare workers are now required to use additional personal protective equipment (PPEs) to protect themselves against the virus. That led to an increased clothing insulation which is negatively affecting the perceived healthcare workers' thermal sensation. OBJECTIVES: While demonstrating through software simulations the potential level of thermal discomfort healthcare workers involved in the COVID-19 emergency can be subjected to, this work aims at identifying measures to improve thermal sensation perception and acceptable thermal conditions for medical personnel. METHODS: After having obtained the insulation values of individual clothing used by staff during COVID-19 emergency through the use of a thermal well-being evaluation software, the Fanger indexes (PMV - Predicted Mean Vote and PPD - Predicted Percentage of Dissatisfied) were calculated in order to estimate staff satisfaction to microclimatic conditions. RESULTS: The use of COVID-19 additional PPEs with an air temperature equal to 22 °C (normally considered optimal) brings the PMV index equal to 0.6, which corresponds to 11.8 % being unsatisfied (PPD) due to perceived heat. DISCUSSION: The use of additional protective devices significantly increases the clothing insulation level, facilitating the onset of conditions of thermal discomfort in the health workers. Workers engaged in the execution of nasopharyngeal swabs were most affected by the summer weather conditions and certainly represent the most critical category, for which it would be recommended to implement a higher turnover of service to reduce individual exposure time and consequent discomfort.

Evaluation of thermal comfort and carbon dioxide levels during ventricular-assist-device implant. / Valutazione del benessere termico e dei livelli di anidride carbonica durante l'impianto di in dispositivo di assistenza ventricolare.

BACKGROUND: Environmental measurements were performed in an operating theatre within a pediatric cardiac department, during a surgical operation involving the use of carbon dioxide for the implantation of a ventricular system (VAD). OBJECTIVES: After some reports from the staff, who were complaining about low temperatures in the operating room, it was decided to check carbon dioxide levels, the conditions of thermal comfort and the presence of draughts. METHODS: Microclimatic parameters and carbon dioxide concentration were performed with a microclimatic unit Delta OHM model HD 32.1. RESULTS: The carbon dioxide concentration values measured during the operation were below the levels at which the working environment was not comfortable, as expressed by both the ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) and the ACGIH (American Conference of Government Industrial Hygienists) standards. PMV (Predicted Mean Vote) and PPD (Preticted Pencentage of Dissatisfied) values obtained indicate a thermal discomfort tendency to cold perception, perceived in particular by the anesthesiologist, circulating nurse and cardiovascular perfusionist. Airflow discomforts occurred at different stages of the operation. CONCLUSIONS: Acting on the air conditioning system, decreasing air velocity, while guaranteeing the minimum number of air recirculation prescribed by the regulations, appears to be the best prevention measure. Changing the mode of laminar air inlet above the cot may, however, affect the "wash" effect of the operating range. Otherwise, a "protective" measure could concern staff clothes, providing them with garments with better insulation, in order to protect the neck area, which is affected by the effects of draughts.

[Shield the work]. / Schermare il lavoro.

Many workers are exposed to direct solar radiation. In these conditions the workers may suffer damage to health due to an excessive increase in body temperature, or to the loss of liquids. Were carried out tests to determine if the use of screens made of various materials can reduce the physiological effects. Using the indexes WBGT and PHS were calculated the internal body temperature and the amount of fluids lost, before and after use of the screen. The best screens were those made of cardboard, newspaper paper and beach umbrellas.

Is driving in a hot vehicle safe?

PURPOSE: This paper investigates the thermal conditions inside a passenger car driven after it was left a few hours in a shade-less parking lot, and the related implications for the driving performance. MATERIALS AND METHODS: Experimental results for twelve tests carried out in four different vehicles are presented and discussed. Each test is characterized by means of the predicted core temperature tcore of the driver after 60 minutes, as calculated by a heat stress model. The fractional performance loss is calculated by adjusting existing algorithms for office tasks to accommodate literature data on driving-related tasks, and then re-casting the algorithm as a function of tcore instead of the air temperature ta. RESULTS: Based on measured temperatures and humidities, fractional performance losses up to 50% are predicted even for relatively simple tasks such as keeping the vehicle on a straight course. Performance losses in excess of 75% are predicted, under the most extreme thermal conditions, for demanding tasks, such as correctly identifying a signal and reacting in due time. CONCLUSIONS: The implementation in technical standards on heat stress assessment of two new thresholds is recommended. The lower threshold, to be set at tcore ≅ 37.1 °C, is aimed at ensuring that the subject is able to carry out demanding mental tasks without appreciable performance loss, while the higher threshold, to be set at tcore ≅ 37.2 °C applies to simpler tasks.

Classification of thermal environments for comfort assessment.

According to ISO 7730:2005, classification is a mandatory precondition for thermal comfort assessment since the appropriate criterion depends on which category the specific work situation (SWS) investigated belongs to. Unfortunately, while the standard does include three different comfort criteria, it does not indicate how the appropriate criterion should be selected. This paper presents a classification scheme that allows thermal comfort assessment to be reliably performed in any environment. The model is based on an algorithm that calculates a score by means of a weighted product of three quantities, each one taking care of a specific, highly relevant element: the subject's thermal sensitivity, the accuracy required for carrying out the task and the practicality of thermal control. The scheme's simple modular structure can easily accommodate both changes and additions, should other hypothetical elements be identified to be as relevant to the classification scheme. The model presented allows a modulation of comfort levels across different social groups. It is so possible to provide extra care for children, elderly, pregnant women, disabled and other 'weak' categories, as required by ISO/TS 14415:2005, by setting the highest comfort level. Finally, it also widens the options for simultaneously establishing comfort conditions for different individuals performing different tasks in the same area and clarifies whose comfort should be pursued with the highest priority.

Thermal comfort assessment in comfort-prone workplaces.

This paper's main issue is a strong advocacy in favour of an a priori classification of thermal environments that can be really functional to comfort assessment: Class 1, environments where comfort conditions can be established (comfort-prone environments), and Class 2, environments where this is not practically feasible. The former, which are also identified here as 'thermally unconstrained' environments, because of the absence of elements preventing comfort from being pursued, are the subject of a novel classification scheme. In assembling such a scheme, the four standardized synthetic indexes (Predicted Mean Vote, Insulation REQuired, Predicted Heat Strain, Wet-Bulb Globe Temperature) have been carefully scrutinized, with special emphasis on the regions of overlap. Additional data from national technical documents and legislation have been used to help in assembling the discomfort assessment scheme. All available information has been reprocessed and cast in a form specific for use in comfort-prone environments. Classification takes place through placement in a four-level and in a six-level discomfort scale for cold and warm environments, respectively; for each area, a recommended descriptor as well as a time frame for intervention are specified. The new scheme also eliminates a few glitches and inconsistencies existing in the ISO 15265 scheme, mostly in the area of cold discomfort. Being solely concerned with comfort-prone environments and keeping an open mind with respect to all available information, the new classification scheme represents a simple and robust all-round tool, tackling issues related to both comfort assessment and to action planning for an optimized allocation of available resources.