Jason Kai Wei Lee

Director, Heat Resilience and Performance Centre, Yong Loo Lin School of Medicine, National University of Singapore

Current Position:

  • - Director, Heat Resilience and Performance Centre, Yong Loo Lin School of Medicine, National University of Singapore
  • - Co-Lead, Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore


  • - 2003 to 2006, PhD, Loughborough University, UK
  • - 2000 to 2003, BSc (1st Class Hons), Loughborough University, UK

Professional Experience:

  • Ongoing only:
  • - Member, Management Committee, Global Heat Health Information Network (2022 to present)
  • - Member, Heat Index-Physical Activity Expert Panel, Ministry of Health (2021 to present)
  • - Member, Singapore National Physical Activity Guidelines Advisory Committee, Health Promotion Board-Sport Singapore (2021 to present)
  • - Member, Technical Committee, National Code of Practice for Sports Safety (2021 to present)
  • - Chair, Sports Advisory Committee, Ministry of Culture, Community and Youth (2020 to present)
  • - Member, Workgroup, WHO and WMO Technical Report on Climate Change on Workers (2019 to present)
  • - Chair, Thermal Factors Scientific Committee, International Commission on Occupational Health (2019 to present)
  • - Member, Board of Directors, Singapore Sports School (2017 to present)

Special Honor:

  • - SAF National Servicemen of the Year Award (2017)
  • - SAF Commando Formation National Serviceman of the Year Award (2014 and 2016)
  • - DSO Big Idea (dBi) Award (2013 and 2017)
  • - Friend of Raffles Institution Award (2013)
  • - Fellow of the American College of Sports Medicine (2012)
  • - DSO Group Performance Award (2008, 2013, 2015 and 2016)
  • - UK Overseas Research Scholarship (2004 to 2006)
  • - Halliwell Development Studentship (2004)
  • - G V Sibley Memorial Prize, Loughborough University (2003)


Ensuring workers' health and performance in a warming world

Climate change will challenge health and productivity of working people. Excessive climate conditions can also increase workplace injury rates. The direct effects of heat on working people are well established in physiological science, but there are gaps in the evidence underpinning quantitative occupational health impact assessments. Problems associated with working people in harsh conditions need to be accurately quantified with practical solutions warranted. Often overlooked, the social impacts of heat at and off workplaces are equally important and must therefore be considered. Economically, we seek to ensure the resultant benefits of heat management solutions to outweigh the implementation cost. 

Occupational heat stress can induce heat illnesses and accidents, and degrade work productivity. Heat stress is mainly dependent on environmental factors, metabolic heat production and type of clothing. The overall physiological responses from heat stress determines heat strain. Environmental determinants alone are therefore insufficient to quantify heat strain. To fully understand the impact of heat on individuals, both behavioural and physiological responses are important. Behavioural thermoregulation should first be considered such as providing work-rest cycles, allowing self-pacing during work etc., coupled with other physiological interventions to reduce heat strain. 

The health and wellbeing of individuals exposed to heat are linked to their thermal comfort and heat strain, encompassing intrinsic factors that should be integrated in assessing the ensuing impacts. Thermal comfort can be degraded due to passive heat stress where an individual may experience a change in skin temperature or sweat rate but often with little change in body core temperature. Heat strain, on the other hand, is often induced by extreme thermal conditions as well as exertional heat stress (due to work or exercise) that result in elevation of body core temperature. Individuals become at risk of heat strain not only when extreme heat exposure is realized, but also when they are exposed to chronic and prolonged heat exposures that increase the body’s core temperature beyond what is tolerable for physiological functioning. 

It is therefore important to achieve a ‘human-centric’ approach, i.e. focusing on personalized characteristics of comfort, well-being, performance, and health. The “one size fits all” approach will incur productivity losses for heat-tolerant individuals while compromising heat-intolerant workers. I will provide an overview on the impact of heat stress on the society. Then I will focus on occupational heat stress, its implications and highlight strategies that can preserve health and performance of workers.