The initial investigations in to the field of thermal comfort focused on the physiological responses of human subjects to changes in their thermal environment. This purely objective study has progressed in recent years, undergoing several shifts in focus, to thermal comfort now being recognised as a primarily subjective entity that is dependent on numerous influencing variables to the extent that it is now often referred to as a state of mind.

The acceptance of thermal comfort perception being a subjective entity has not however resulted in a change to its measurement which remains established as a linear relationship between indoor comfort and the objective outdoor environmental parameters of Temperature and Relative Humidity, and few if any of the subjective influencing variables have been quantified.

The work undertaken in this thesis addresses these discrepancies in existing scholarship. The primary focus is on establishing and quantifying the variables that influence subjective thermal comfort perception as experienced by the populations of the primary case study region (developing world regions that are exposed to hot-dry climatic conditions). Extensive statistical analysis of the empirical data of the thermal environments and their occupants’ thermal comfort perception and associated variables was undertaken to assess the effect of socio-economic status on one’s perception of their physical environment, and in to the influence of prolonged exposure to particular physical environmental parameters on a population’s expectation and consequent perception of the thermal environment.

The predictive accuracy of the traditional thermal comfort equations using both historically archived data as well as empirically collected data from the case study site is also assessed, and through a detailed statistical analysis, the best fit mathematical formula that explains thermal comfort perception with respect to the relevant outdoor environmental parameters is established.

This thesis moves the field of thermal comfort studies forward with new knowledge drawn from empirical data. The main findings of this thesis (specific to the case study area of Lahore Pakistan) are:

- Although thermal comfort is a climatically defined entity, it is also culturally specific with significant variations in thermal comfort perception existing between the different populations resident within a climatic zone.

- Previous exposure to different thermal environments has been shown to significantly influence an individuals’ perception of their current thermal environment and consequently the parameters within which they perceive thermal comfort.

- Significant variation in thermal comfort perception exists between populations of different socio-economic position within a climatically and culturally specific region.