Heat Stress Concerning Welders
For as long as welding has been used in metal fabrication, protecting workers from severe heat exposure has been a major concern. The welder’s head and face are often within two feet of the welding arc, which can reach a staggering 6,500 degrees Fahrenheit. All the while, the welder is wearing a helmet and other protective gear, 10 pounds or more in total, that trap their natural body heat. While intense heat can certainly be irritating for the welder, the impact is more than an issue of comfort. There are significant safety, liability and productivity considerations as well.
When the outside temperature increases, the body tries to cool off by directing more blood just under the skin and by perspiring. When the body is no longer able to keep its temperature in check, a condition called heat stress sets in and the effects can be severe. Symptoms include irritability, weakness, shivering and disorientation. Prolonged exposure may result in heat stroke, which is characterized by chills, convulsions and a loss of consciousness.
Even in less severe circumstances where clear physical symptoms aren’t evident, intense heat can affect the welder’s ability to perform his or her work successfully. A growing body of research indicates that heat stress hinders one’s ability to concentrate and perform tasks that require even a moderate level of skill. As a result, employees work at a slower pace and with less accuracy. Because welding is often used in applications where bond strength is critical, the significance of each error is magnified. Mistakes that go undetected can not only damage the company’s reputation for reliability and quality, but can be a liability and cause danger if a critical weld is made with less accuracy. Even those that are caught can be costly to correct, and neither outcome is one today’s companies can afford.
Naturally, manufacturers and fabricators have taken a number of measures over the years to combat heat exposure, such as installing air conditioning systems, using fans for spot cooling and controlling humidity with dehumidifiers. While these measures have been somewhat effective, each comes with certain limitations as well. For instance, it can sometimes take up to 24 hours for someone to fully rehydrate by consuming fluids, and repeated trips to get water can curb productivity and create production bottlenecks. Vests that expose the chest and back to cool water can lower body temperature, but are heavy, cumbersome to wear all day and can create productivity challenges of their own since refilling may be frequently required.
How Does Heat Stress Affect Productivity?
Because of the prolonged exposure to heat experienced by welders, when temperatures rise above 90 degrees, heat cramps and sunstroke are possible with lengthy physical activity; above 105 degrees, these conditions become probable.
However, heat can have a detrimental effect on mental activity and motor skills, even before bodily symptoms are present. A number of studies over the years have addressed the impact of heat exposure on worker performance. The clear conclusion from this body of research is that employees become not only less productive, but also less accurate, when the air temperature around them is well above the comfort range.
In cases where the research subjects were exposed to temperatures of 90 degrees or higher, the reduction in performance was as high as 15 percent when compared to normal conditions.
Increased errors can have a substantial financial impact on a business with welders. To give a hypothetical example, if a crew working at 95 degrees makes 100 errors in a week, and the cost of correcting each mistake is $20, the cost of those errors is $2,000 during that stretch. If you could reduce welders’ temperature to 80 degrees, the number of heat-related errors could be reduced to 10, for a total cost of $200. That translates to a total savings of $1,800 per week. Even if the number of errors were reduced by just 50 percent, the company saves $1,000 each and every week.
What Steps Can You Take?
Given the health risks and detriment to performance associated with lengthy heat exposure, manufacturers are looking for cost-effective ways to keep their welders cool. Taking breaks and consuming liquids throughout the day can certainly be part of the solution, although rehydrating the body can result in lost productivity. The preferred approach is one that keeps the employee comfortable and operating at peak performance without sacrificing total output. A significant downside of cooling vests that some welders use is their size and weight, which can make the worker uncomfortable and actually increase fatigue.
The TENNESSEE CHILL BOX is the only logical choice for respirator protection. Please allow us to share our history with you, and explain the benefits of our systems. Visit us at www.tennesseechillbox.com or call our office at 423-710-1476.
Mike Asbra, Inventor
- Centers for Disease Control & the Bureau of Labor Statistics
- U.S. Department of Labor
- National Oceanic and Atmospheric Association
- J.J., Nadler, E. and Busch, C., 2002, Effects of hot and cold temperature
- Seppanen, O., Fisk, W.J. and Faulkner, D., 2003. Cost benefit and analysis of the night-time ventilative cooling in office buildings. Lawrence Berkeley National Laboratory.
- Mackworth, N.H., 1946. Effects of heat on wireless telegraphy operators hearing and recording Morse messages. British Journal of Industrial Medicine, 3, 143-158.