It is important to understand workers’ perceptions on workplace extreme heat exposure in a warming climate, as this information may provide evidence for updating heat prevention strategies to reduce the impact of climate change on workers’ health and safety. However, most of the currently available information is from qualitative studies in middle-low income countries [
24‐
26]. Limited evidence suggests that workers’ perceptions regarding likely increasing extreme heat exposure due to climate change in high income countries are not optimistic [
11]. This survey is a modest step to investigate workers’ heat risk perceptions in a developed country, using a quantitative approach.
Workplace heat exposure concern in Australia
This study revealed that about half of the respondents were moderately to very much concerned about their occupational health and safety when working during very hot weather. The percentage (50 %) concerned in those participants employed in the “agriculture, forestry and fishing” industry in this study was about 6 times higher than that (8 %) in a study of Californian hired farmworkers in the USA [
27]. The relatively higher heat awareness among the Australian workplace may reflect cultural and demographic differences in study populations.
Our results suggest that young workers were less concerned about heat exposure than older workers. Moreover, middle aged workers supported having more heat-related training compared to young and older workers. There are many concerns about Australian young workers’ attitudes towards occupational health and safety, of which heat stress is only one. According to the national “Motivations, Attitudes, Perceptions and Skills” survey, up to 28 % of Australian young workers reported resenting dealing with workplace health and safety requirements, and 42 % forgot about safety during working practice [
28]. Evidence has shown that young workers are at high risk of heat-related illnesses and injuries when the temperature is below a certain threshold (e.g., 37.9 °C) [
2,
4,
5]. By contrast, older workers are more vulnerable to heat-related illnesses/injuries in certain outdoor industries during heatwaves [
3]. Therefore, more educational programmes should be targeted to these two age groups. Further research is also needed to explore the paradoxical phenomena that young workers were less satisfied with heat prevention measures but expressed more negative attitudes towards heat prevention efforts, compared with older workers. Probably, it is because young workers were relatively more powerless than older workers in the workplace and held negative attitudes towards their management [
21]. The compliance and implementation of heat prevention and adaptation policies would be undermined if the sentiments of unwillingness to cooperate existed among young workers [
28].
Undertaking very physically demanding work and wearing PPE was also found to be associated with workers’ concern about heat exposure. Both of these are very important factors determining human body heat balance, and can be indirectly reflected in the standard workplace heat stress management procedure [
8]. The results also suggest that workers who had a previous heat-related illness and/or injury were more concerned about heat exposure.
In this study, about 43 % of respondents indicated that they have received heat-related training. The relatively higher proportion of workers receiving heat prevention training in this study maybe partly because of the lessons learnt from the past. Previously, less OH&S training and education had been provided in Australian workplaces, and this was identified as one of the top three causes of occupational injuries and accidents in Australia [
29]. Therefore, relevant work health and safety training has been incorporated into secondary, vocational and university level education since the mid-to late 1990s in Australia [
29].
The results indicated that heat training was the workers’ major source of information about heat stress prevention in Australia, and this is the case for occupational health and safety in general [
29]. Evidence has suggested that the majority of outdoor physical workers in the USA [
27,
30], India [
26] and South Africa [
24] had a good knowledge of the symptoms and severe outcomes of excessive heat exposure [
24,
27,
30]. Although workers’ average level of knowledge on heat stress wasn’t investigated in this study, 16 % of respondents said they only drank when they were thirsty. This indirectly reflects the necessity to reinforce messages about dehydration in the workplace. Relevant training and education should focus on young workers and those aged over 55 years, as these groups expressed less willingness to receive more heat training. Moreover, studies have shown they are at relatively higher risk of heat-related illness and injury [
2‐
4]. More supportive attitudes towards heat-related training in the age group of 25–54 years may account for their greater concerns over heat exposure. The reasons why workers aged ≥55 years did not show stronger willingness to support more heat-related training whilst being more concerned about heat compared to young workers, may include that they may be more satisfied with current preventive measures in place or they may undertake more sedentary jobs with less heat exposure. In addition to training in the workplace, the role of mass media in popularizing heat stress prevention knowledge should be strengthened, as up to 10 % of respondents in this study claimed to have had no sources of heat prevention information.
Individual behavioural response
The majority of respondents expressed their willingness to adjust work habits to adapt to possible increasing hot weather, and this may be useful for future heat intervention measures. The results from this study suggested that previous heat illness experience was the only factor associated with the adjustment of work habits, indicating a need for improving heat risk awareness. Moreover, a good level of heat stress knowledge and awareness does not necessarily translate into individual behavioural change [
30]. The knowledge-behaviour gaps may provide opportunities for additional heat prevention and education strategies.
In other studies, self-pacing (adjusting work rate to avoid physiological heat strain) has been used to explain why workers were not heat stressed when working in hot environments [
13,
31]. In the present study, up to 70 % of respondents expressed that they worked at their own pace during very hot weather. For others, pressure from work demand and supervisors was the major reason that workers did not slow down their work rate. Most recently, Lao et al. interviewed 32 male council workers in South Australia and found they had a high level of heat resilience through personal adaptive behaviours [
21]. Nevertheless, profit-oriented production and performance targets have been shown to be a common reason overshadowing or marginalizing heat stress prevention [
11,
21]. Employee-based behavioural change is not enough to reduce heat-related illness and injury, as employees may be powerless in an occupational health and safety management system [
11,
21,
32]. Relevant heat prevention campaigns and legislations should target employers as heat stress not only impacts workers’ health and safety but also may compromise productivity [
1,
6,
11,
12,
33]. However, to date few studies have investigated how employers in industry perceive the risk of heat exposure, although results of our recently published paper showed that the majority of occupational hygienists and specialists in Australia were concerned about workplace extreme heat exposure [
34].
Heat prevention measures
In this study about one-quarter of respondents claimed to have witnessed heat-related illnesses or injuries during extremely hot weather. This may indirectly reflect the high incidence of occupational heat illnesses despite only 306 heat-related compensation claims being identified in South Australia during the period of 2001–2010 with an incidence rate of 4.5 per 100 000 employees [
35]. This figure may be underestimated due to underreporting and misclassification [
13]. Fortunately, all heat-related illnesses, injuries and deaths are largely preventable. Heat prevention strategies mainly include regulations, administrative controls, and engineering modifications. Currently, there are systematic technical guidelines and manuals in place for heat stress monitoring, risk assessment, control and prevention, such as ISO (International Organization for Standardization) heat indices [
36], ACGIH (American Conference of Governmental Industrial Hygienists) [
37] and NIOSH (US National Institute for Occupational Safety and Health) heat standards [
38]. Based on above heat standards, the Australian Institute of Occupational Hygienists (AIOH) has developed a heat stress management guideline for use in the Australian environment [
8]. However, it should be realized that these guidelines and technical manuals do not have a legal force.
It has been proven that without proper enforcement heat regulations are likely to pose little restrictions to non-compliant employers [
39,
40]. In 2010, California became the first State in the USA to enact a stringent heat-specific law to protect workers from heat exposure [
41]. Two years later however, inspectors found that more than half of the employers they audited did not comply with the heat standard [
42]. Heat prevention measures seem straightforward, common-sense, and simple (e.g., drinking water frequently, wearing light coloured and permeable clothes, taking breaks in the shade, and responding to early symptoms). However, a variety of factors at multiple levels in the workplace may constrain such implementation, such as production quotas, worries of being considered ‘soft’, and workers’ fears of losing their job [
11,
21,
39]. Currently, there is no federal occupational standard specifically addressing heat illness and injury prevention in Australia [
12,
35], which may make the implementation of heat prevention measures problematic.
Maintaining hydration is very important for heat prevention. In this study, approximately 30 % of respondents replied that cool drinking water was not available in the workplace. Moreover, about 16 % of respondents only drank when thirsty. Thirst cannot be relied upon as a guide for the need for water, as 1 % of the total body weight in water is already lost when an individual senses thirst [
43]. According to the national Model Code of Practice (managing the work environment and facilities) [
44], “an adequate supply of clean drinking water must be provided free of charge for workers at all times.” However, its implementation and effectiveness are questionable, as evidence has shown that a poor hydration status has been observed among workers employed in a range of industries in Australia [
45,
46].
Our results showed that only 20 % of respondents selected “stopping work” as a heat prevention measure when the temperature was extremely hot. However, according to the heat stress management policy of the Construction, Forestry, Mining and Energy Union (CFMEU) South Australia Branch, “if temperature is over 37 °C all work ceases unless working in an air conditioned area” [
47]. In this study, the majority (67 %) of participants were recruited from agriculture, forestry, mining, construction, and “electricity, gas and water” industries, and about half worked outdoors. Therefore, this raises concerns regarding the compliance of heat policies.
In this study, about 64 % of respondents thought there was a need for more heat-related regulations. Meanwhile, about half the respondents were not satisfied with current prevention measures, indicating the necessity and urgency of the development of heat policies, especially for young workers with low education levels and undertaking physically demanding work outdoors. Most recently, Jia and Rowlinson et al. [
48] formulated a comprehensive socio-ergonomic framework for identifying heat risk factors in the construction industry, and suggested a set of localized, simplified, action-triggering and threshold-based guidelines for the development of current heat management system [
49]. This may provide useful inspirations for developing more effective and practical heat stress management for the construction industry and other at-risk industries. Therefore, in addition to strengthening the implementation of current existing regulations during extremely hot days, more efforts are needed to develop local industry specific heat stress policies [
49].
Limitations
There are several limitations in this study. First, the vast majority (96 %) of respondents were males. Caution should be used when generalizing the results to female workers. Moreover, as the participation of the survey was completely voluntary, those with previous heat illness and injury experience may have been more likely to participate in the survey, which may generate potential selection bias and therefore may overestimate workers’ heat concerns. Second, the level of workers’ heat-related knowledge was not specifically measured in this study. However, published papers have consistently found that most workers in both developing and developed countries have a good knowledge of heat illnesses [
24,
27,
30,
50]. Third, the relatively low response rate (50.9 %) in this study may generate potential non-respondent bias. Although there is not necessarily a relationship between response rates and bias, non-response bias may occur if respondents significantly differ from non-respondents [
51]. Fourth, 68.2 % of participants were TAFE trainees rather than established workers, although the majority worked as apprentices on a part-time basis. Lastly, the survey was not conducted during the hottest part of the year, posing the opportunity for recall bias.