Mercury rising: why science is warming to workplace temperature

Amid Europe’s dangerously dry summer weather and the UK’s record highs, temperature is a ‘hot’ topic – but even without an unusually warm period, temperatures in the workplace are a frequent topic of discussion among colleagues.

The influence of air temperature on how humans think and behave has been thoroughly investigated by cognitive scientists and their findings indicate that both absolute temperatures and perceptions/contexts influence the implications of ambient conditions.  Design can make particular thermal conditions more or less likely. Here are some basic scientific considerations:

Best for performance: Research consistently indicates that air temperatures between 68 and 74 degrees Fahrenheit, coupled with humidity levels from 40 to 70 per cent, are best for our cognitive performance (Baker [University of California, Berkeley] and Bernstein [McGraw Hill Construction], 2012).

Staff control: The World Green Building Council, in reporting on features of healthier and greener offices (2016), share that  ‘healthy offices have a comfortable temperature range which staff can control.  Why?  6 per cent fall in staff performance when offices are too hot and 4 per cent if too cold.’

Subjective preference: Employees’ professional performance is best when they’re in a space whose temperature aligns with what they prefer (Sellaro, Hommel, Manai, and Colzato 2015).  The Sellaro-led team found that ‘subjective preferences are more reliable predictors of performance than objective temperature and that performing under the preferred temperature may counteract “ego-depletion” (reduced self-control after an exhausting cognitive task) when substantial cognitive control is required.’ All researchers are from the Institute for Psychological Research, Leiden Institute for Brain and Cognition, Leiden University, The Netherlands.

Subject to change: Letting people control the temperature in their workplace is desirable (Shahzad, Brennan, and Theodossopoulos, 2014). Shahzad (from the University of Sheffield) and colleagues found that ‘the thermal preference of occupants [during any particular workday] is subject to change . . . individual thermal control in the workplace is more likely to increase user comfort and satisfaction.’  They learned that ‘Over half of . . . [study participants] did not have a steady thermal preference during the day, preferring different thermal settings at different times.’ Research was conducted in cellular offices where workers had ‘control over a window, heating and cooling’ and in open offices ‘with limited operable windows for users seated around the perimeter of the building’.

Adaptive comfort: A team based at the Center for the Built Environment at the University of California, Berkeley evaluated user experiences in the earth-friendly building that houses the Carnegie Institute for Global Ecology at Stanford University (Weeks, Lehrer, and Bean, 2007). The group reports that temperatures in the building are sometimes over 76 degrees Fahrenheit but there hadn’t been complaints about these temperatures. The researchers state that ‘This situation supports the theory of adaptive comfort, which states that in naturally ventilated buildings – where occupants are connected more closely to the outdoor conditions, have more control over windows, and access to increased air movement – people will stay satisfied in conditions outside of the comfort range of 68 to 72 degrees F.’

Thermal adaptability: Life experiences also influence impressions formed of temperature in a space.  De Dear (University of Sydney) and his team studied primary and secondary school students’ assessments of the temperatures in schools (2015).  The researchers found that ‘An indoor operative temperature of about 22.5°C was found to be the students’ neutral and preferred temperature, which is generally cooler than expected for adults. . . Despite the lower-than-expected neutrality, the school children demonstrated considerable adaptability to indoor temperature variations. . . the present analysis indicates an acceptable summertime range for Australian students from 19.5 to 26.6°C. . . . with students in locations exposed to wider weather variations showing greater thermal adaptability than those in more equable weather districts.’

Subtle influences of temperature

The temperatures we are experiencing influence us in sometimes unexpected, and intriguing, ways. For example:

We’re more likely to go along with other people’s opinions when we’re comfortably warm than when we’re comfortably cool (Huang [Nanyang Technological University], Zhang, Hui, and Wyer, 2012).

Syndicus (Aachen University), Wiese and van Treeck found that experience of temperatures influence risk taking (2018).  The team reports that when ‘two groups . . . completed the aforementioned tasks either in a warm (≥ 30°C) or neutral (≤ 25°C) ambient temperature condition, participants made significantly riskier decisions in the warm ambient temperature condition. . . . Especially elevated ambient temperatures should, therefore, be monitored in office environments to prevent impairments of decision making’.

Syndicus, Wiese and van Treeck (2018) also collected information ‘in an office-like environment in one of the three temperature conditions. The comfort condition . . . featured an average air temperature of 24 °C [75 degrees Fahrenheit]. The elevated ambient temperature condition was 28 °C  [82 degrees Fahrenheit]. . . Condition three employed an airstream of approximately 0.8 meters per second, intended to compensate for performance decrements at the elevated air temperature (28 °C). . . . Participants in the warm condition were significantly less persistent [on the cognitive task they’d been asked to work on] compared with participants in the control [comfort] and compensation conditions . . . the airstream seemed to compensate for the higher temperature. Participants’ persistence in the compensation and comfort conditions did not differ.’

Temperature influences whether we’re more likely to make emotion- or cognition-based decisions (Hadi, King and Block, 2015).  Hadi (Baruch College) and her team found that ‘cold (warm) temperatures may lead individuals to rely more (less) on emotions when making decisions’.  So, cold people are more likely to make emotion-based decisions and the reverse is true for those who are warm.

‘People who feel cold are less likely to make rational rather than emotional decisions…’

Garreton (Consejo Nacional de Investigaciones Cientificas y Tecnicas), Rodriguez and Pattini linked perceived indoor temperatures and perceptions of visual glare (2016). As they report ‘volunteers . . . performed an office-like computer task. Three scenarios with sunspots over the desk were evaluated:  a cold scenario, a comfortable scenario and a hot scenario. . . the perceived temperature affected glare. In short, ‘when participants were exposed to a hot environment, the probability of occurrence of discomfort glare was more than 2.5 times higher in relation to a thermally comfortable environment.

Fetterman (University of Texas El Paso) and his team rigorously established a relationship between physical and social warmth (research in press). They report that ‘On days in which participants felt physically warmer, they perceived themselves to be interpersonally warmer and more agreeable, irrespective of the outdoor temperature. . .We asked people about their subjective feelings rather than actual body temperature, as this is the sort of information that people have access to. How warm or cold people feel on particular days is likely determined by a number of factors, including weather, dress, and activity level.’

In conclusion, the scientific evidence suggests that the temperature of the space that we’re in influences our physical comfort as well as how we think and behave, often in fascinating ways.

Sources:

Lindsay Baker and Harvey Bernstein.  2012.  ‘The Impact of School Buildings on Student Health and Performance:  A Call for Research.’

Richard de Dear, Jungsoo Kim, Christhina Candido and Max Deuble.  2015. ‘Adaptive Thermal Comfort in Australian School Classrooms.’  Building Research and Information, vol. 43, no. 3, pp. 383-398.

Adam Fetterman, Benjamin Wilkowski and Michael Robinson. ‘On Feeling Warm and Being Warm:  Daily Perceptions of Physical Warmth Fluctuate with Interpersonal Warmth.’  Social Psychological and Personality Science, in press.

Julieta Garreton, Roberto Rodriguez and Andrea Pattini.  2016. ‘Effects of Perceived indoor Temperature on Daylight Glare Perception.’  Building Research and Information, vol. 44, no. 8, pp. 907-919.

Rhonda Hadi, Dan King and Lauren Block.  2015. ‘Mental Thermoregulation:  Affective and Cognitive Pathways for Non-Physical Temperature Regulation.’  Conference Proceedings, Society for Consumer Psychology, pp. 155-157

Xun Huang, Meng Zhang, Michael Hui and Robert Wyer.  2012.  ‘Ambient Temperature and Conformity in Financial Decisions.’  Proceedings, Annual Winter Conference, Society for Consumer Psychology, February 16-18, Las Vegas, pp. 311-312.

Roberta Sellaro, Bernhard Hommel, Meriem Manai and Lorenza Colzato.  2015. ‘Preferred, But Not Objective Temperature Predicts Working Memory Depletion.’  Psychological Research, vol. 79, pp. 282-288.

Sally Shahzad, John Brennan and Dimitris Theodossopoulos.  2014. ‘Individual Thermal Control in the Workplace and Changes in Thermal Preferences in a Day:  Norwegian Cellular vs. British Open Plan Layouts.’  Proceedings of the 8th Windsor Conference:  Counting the Cost of Comfort in a Changing World, Windsor, UK, April 10-13.  

Marc Syndicus, Bettina Wiese and Christoph van Treeck. 2018. ‘In the Heat and Noise of the Moment:  Effects on Risky Decision Making.’ Environment and Behavior, vol. 50, no. 1, pp. 3-27.

Marc Syndicus, Bettina Wiese and Christoph van Treeck. 2018. ‘Too Hot to Carry On?  Disinclination to Persist at a Task in a Warm Office Environment.’  Ergonomics, vol. 61, no. 4, pp. 476-481, doi:  10.1080/00140139.2017

Kirsten Weeks, David Lehrer, and Jonathon Bean. 2007. ‘A Model Success: The Carnegie Institute for Global Ecology.’ Center for the Built Environment, University of California, Berkeley

World Green Building Council.  2016.  ‘Building the Business Case:  Health, Wellbeing and Productivity in Green Offices’