Thermal Environment M502 (replaces W502 OHTA course)

This examination aims to provide you with a sound understanding of the effects of the thermal environment on people, and the means of assessing and controlling the risks associated with thermal stress

Who is it for?

This examination is for the following: 

  • Suitable for technicians and technologists who carry out measurements and testing in workplaces. 

How to prepare

Candidates can prepare by self-study, but are recommended to follow appropriate in-company training, University course or other course provided by a reputable training provider.

Learning objectives 

On completing this examination successfully, you will be able to: 

  • Identify sources of thermal stress within the working environment; 
  • Understand the nature of thermal strain on the body; 
  • Make an assessment of the thermal environment through appropriate measurement and other means; 
  • Evaluate the likely risk from exposure to thermal stress; 
  • Suggest appropriate control approaches for the thermal environment. 


There will be a 40 short answer question ‘open book’ examination with an allowed time of 120 minutes. 

M502 is recognised for the purpose of professional training and education by the Faculty of Occupational Hygiene, the Professional Standards Body for UK Occupational Hygiene, Chartered Professional Body and statutory body for the recognition in the UK of overseas professional qualifications in Industrial/Occupational Hygiene.

BOHS is no longer an authorised examining body for the OHTA W502 module or part of the OHTA international training scheme and qualifications framework.

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