Construction workers are particularly susceptible to heat-related illnesses, for the weather is very hot and humid. The objective of this study is to investigate the interaction between the temperature and relative humidity to the physiological parameters such as heart rate (HR) and volume oxygen uptake (VO2 max) of the workers in the construction industry. The experiment was conducted in an environmental chamber which simulates the environment of the construction industry with three conditions combining air temperature and relative humidity (34 °C/74 %, 34 °C/92 %, 38 °C/83 %). The HR and the VO2 max of three subjects were monitored, and all the data were continuously recorded every 15 minutes. For each condition, the activity levels such as lifting the heavy sand (10 kg) were conducted for subjects. In the VO2 case, a significant correlation was observed between air temperature (p=0.043) and the relative humidity (p=0.000). Meanwhile, in HR case, a significant correlation was also observed between air temperature (p=0.004) and the relative humidity (p=0.028). The high-risk thermal environment (38 °C/83 %) and subject were identified. In conclusion, it can be empirically proved that environmental factor such as temperature and relative humidity have a significant impact on workers’ performance.

The study on heat stress and heat strain has been conducted since early 20th century. However, in the current years, it attracts an increase of attention around the world mainly due to the global climate change issues. Traditionally, there are two main approaches in the study of heat stress and heat strain which are the climatic chamber studies and the field studies. But, with the recent development in the computational fluid dynamic (CFD) simulation, the researchers shift toward this approach as a new method for the study of heat stress and heat strain. Climatic chamber can be simulated with various environmental parameters such as air flow and heat transfer while a manikin is used to identify the effects of these parameters. In this study, recent developments of the CFD simulation for the study of heat stress and heat strain for indoor environment are reviewed while their methodology and results are compared. The discussions that will be presented in this work will focus on the various CFD techniques and its significance as a new method for the study of heat stress and heat strain.

Excessive heat during work creates occupational health risks; it restricts a worker’s physical functions and capabilities, work capacity and productivity. Temperatures above 24–26 °C are associated with reduced labour productivity. Exposure to excessive heat levels can lead to heatstroke, sometimes even with a fatal outcome. The aim of this study is to discuss the methodology in experimental of the factor affecting heat stress in industrial workers exposed to extreme heat. The experiment will be conducted in an environmental chamber which simulates the same environment of the manufacturing industry and another arrangement which simulates the environment of a construction industry. The environmental parameters will be recorded such as the temperature, relative humidity and also the physiological parameters such as the volume oxygen uptake level and the heart rate. The heart rate and the volume of oxygen uptake will be recorded for a 15-minute interval for one shift (2 shift-manufacturing and construction). This study is conducted based on two tasks in two different conditions, outdoor and indoor. It simulates the lifting work at both manufacturing and construction industry. For manufacturing industry, the subjects are demanded to lift boxes (10kg). Meanwhile, for the construction industry, the subjects are demanded to lift a sand bag (10kg). From this study, the optimum values of temperature and humidity can be obtained which can lead to the optimum workers’ performance. The increase of performance will ensure the production level at the manufacturing industries at its best and will lead to monetary gain. Besides, this can ensure that a construction project can be delivered at the right time while reducing the cost lost and the accidents at the site.