According to a recent interview in the Sydney Morning Herald, Dr Martin Cope of the CSIRO Marine and Atmospheric Research noted that there are ”… currently about a thousand deaths a year in Australia due to heat stress and related illnesses”
This is hardly surprising, since the human body is designed to maintain a core body temperature of 37 degrees Celsius.
Therefore, anyone carrying out physical activity is potentially at risk.
Thus the creation of metabolic heat inside the body, which needs to be transferred to the person’s external environment in order to avoid a dangerous increase of core body temperature, or ‘Human Heat Balance’, is of prime importance.
The human heat balance is determined by six factors: (1) The ambient air temperature; (2) The radiant temperature; (3) The relative humidity; (4) The air movement; (5) The clothing worn; and (6) The metabolic heat generated by physical activity.
And although this may vary from person to person, according to the yet unpublished study by Lemke, Kjellstrom and Liljegren et al, “if cooling via sweating and convection is not sufficient, the metabolic heat generation needs to be reduced to avoid heat strain and heat stroke.
This creates limits to the extent to which physical activity and work output can be maintained without rest periods.”
So when physical activity is high in a hot working environment, workers will be at risk of increased core body temperature, diminished physical work capacity and mental task ability, increased accident risk and eventually heat exhaustion or heat stroke.
The main factor underlying these effects, according to the study is the “increased core body temperature, but dehydration due to sweating and inadequate liquid intake are also of major importance.
Symptomatic exhaustion and even kidney disease can be the result of excessive dehydration”.
When the human body temperature exceeds 39 degrees Celsius, these acute heat disorders (or heat stroke) may occur, and above 40.6 degrees Celsius life- threatening or ‘severe hyperpyrexia’ results.
In indoor environments, such as offices, increased heat exposure reduces performance and even reducing humidity of office air has been shown to improve the perception of workers--heat and discomfort are hardly inducements for a productive work output.
More seriously, heat stress occurs when the body’s means of controlling its internal temperature starts to fail.
As well as air temperature, factors such as work rate, humidity and clothing worn while working may lead to heat stress.
Heat stress can affect individuals in many different ways, and some people are more susceptible to it than others.
Typical symptoms include an inability to concentrate; muscle cramps; heat rash; severe thirst; fainting; heat exhaustion; fatigue, giddiness, nausea, headache, moist skin; heat stroke; hot dry skin, confusion, convulsions and eventual loss of consciousness.
This is the most severe disorder and can result in death if not detected at an early stage. To combat this kind of scenario, several strategies are needed.
Firstly, encouraging workers in increase their fluid intake is a good start. Secondly, giving workers periodic rests from physical activity will also prove beneficial.
Thirdly, and perhaps most importantly, the regulation of the air temperature in the workplace can and will save lives.
According to Mr. John Sweeny from Active Air Rentals, many people are so used to the heat in some parts of Australia that they forget that it too can become a killer, and quite quickly at that.
“Overseas”, says Mr. Sweeny, “ there is a much higher awareness of the dangers of heat stress, but in Australia, it’s taken for granted since we believe that somehow, living in this sunburnt country, we are immune from basic human sensitivities.”
The fact is, notes Mr. Sweeny, “that any type of physical exertion requires a commensurate cooling of the now heated human body and the fastest way to achieve this is by regulating the air temperature.”
And, he points out, “…The fastest and as yet safest way to regulate the ambient temperature of any space, as well as humidity, is by the use of air conditioning.”
“If you are working in an area like an event marquee, mine, warehouse, retail space or even in a large office, the use of portable air conditioning units is now not only well known, its also part of the various OH&S statutes that they should be used,” concludes Mr. Sweeny.
For more information, contact John Sweeny Business Development Manager, 0402 068 131 or 9319 4422 www.ActiveAir.com.au or email: john@ActiveAir.com.au
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