Employee Exposure to Thermal Stressors - OSH4308-15C-1 Unit 5 Project

OSH4308-15C-1 Unit 5 Project 1
Employees Exposure to Thermal Stressors
Faisal Ahmed
Columbia Southern University

OSH4308-15C-1 Unit 5 Project 2
Introduction and Background
Studies by Katzenberger et al (2014) have defined thermal stressors as the change in
temperature which causes unfavorable as well as undesirable conditions to both human beings
and other living organisms. When the temperatures are very high, the human body tends to react
so as to get rid of the excess heat but as the body temperature increases the individual in question
will experience heat stress. Most researchers have established that the thermal stress due to cold
and heat in most cases affect the health and productivity in the various aspects such as
environmental and working conditions.
The health risks of thermal stressors specifically occur in the outer zones of heat and cold
stress. Individuals, therefore, undergo physiological changes so as to get used to such changes.
The security personnel at Acme Company are experiencing various challenges due to the thermal
stressors hence prompting the company to conduct a study related to the issue. This study was
therefore carried out to determine the employee exposure to various thermal stressors at Acme
Manufacturing Company. This was done by calculating the Wind Chill factor and the Wet Bulb
Globe Temperature for each category of the security personnel.
Report Details
The Wind Chill Factor
According to Shabat, Shitzer & Fiala (2014), the wind chill factor is a calculation of how
the temperature is experienced on exposed skin as a result of wind. It measures the rate at which
the skin loses heat when it is exposed to air and therefore an increase in the speed of the wing
also increases the loss of heat. During cold winter the wind chill factor makes people feel colder
than the normal air temperature. A boundary layer insulates the skin on a calm day making the

OSH4308-15C-1 Unit 5 Project 3
human body warm but when it is windy, the boundary layer is blown away by wind making skin
temperature to drop hence people feel cold. The previous studies conducted show that the skin
loses heat much faster when it is wet than when it is dry. The wind chill factor is very relevant in
a very cold climate since it aids in the survival of animals and humans.
The Wet Bulb Globe Temperature (WBGT)
Wet Bulb Globe Temperature (WBGT) – This heat stress index was developed by the US
Navy in a study on the heat-related injuries during military training. this measures heat stress in
the direct sunlight and therefore takes into account temperature, humidity, the speed of the wind
and solar radiation. It is the commonly used index of heat stress although the users do not seem
to know its limitation. According to Jafari et al (2014), the limitation of the (WBGT) is that
when sweat evaporation of is restricted by low movement of wind or high humidity. It is also
inaccurate due to errors of measurement resulting from the omission of global temperature and
therefore WBGT only provides a guideline to the expected heat effects.
Measuring Wet Globe Temperature
WBGT is determined by measuring three temperatures with a standard thermometer as follows:
(i) Dry Bulb Temperature- is measured with the normal thermometer
(ii) Wet Bulb Temperature- measured with thermometer whose bulb is wrapped with the
wet cotton sleeve.
(iii) Globe temperature-measured with a thermometer placed inside a large black globe.
WBGT is expressed in oC or in oF and it is calculated using the formula given below:
WBGT=0.7WB+0.2GT+0.1DB
However, when the WBGT is measured inside a building where there is no direct solar radiation,
it will be calculated as: