Recognition and Prevention of Heat Stress

As summer approaches, it’s time to think more about heat precautions in the workplace.

• By Andy Olson
• Jun 01, 2021

As temperatures outside rise during the summer months, industrial facilities can face major challenges controlling temperatures inside. Not only do excessively warm work conditions put the health of employees at risk, but they may also cause compliance and insurance issues, as well as facilitate product-damaging mistakes. As the accelerating growth of e-commerce only heightens these issues by accelerating the pace of employee activity, facilities should take steps to ensure a comfortable and cool workplace this summer.

Thankfully, there are several solutions for controlling indoor air quality and temperature, ranging from high-volume, low-speed (HVLS) fans and fabric curtain walls to loading dock seals and fabric ductwork systems. These products can help with environmental control, as well as isolate conditioned and non-conditioned air work zones, thus helping reduce the potential for heat stress and its negative ripple effects on the organization.

The Signs of Heat Stress

Heat stress can present itself in a variety of ways, and while some are less severe, they are all potentially dangerous. The mildest forms are heat fatigue, in which workers begin to lose concentration and perform erratically, and heat rash, which occurs when sweat ducts get plugged and skin becomes agitated and painful. Heat stress may also cause heat cramps in the back, arms, legs and abdomen. Dehydration and electrolyte imbalance caused by prolonged sweating are typically its causes.

More serious risks include heat exhaustion, heat syncope (fainting) and heat stroke. Heat syncope causes the person to faint because the pooling of blood in the lower extremities and dilated vessels in the skin lead to low blood pressure. Heat exhaustion can occur singularly or as part of syncope. Common symptoms include not only fainting but also diarrhea, nausea and disorientation. The most serious heat disorder is heat stroke, which occurs when the body’s systems of temperature regulation fail, and the internal body heat rises to deadly levels. Warning signs include confusion, fainting, convulsions and/or an absence of sweat. If a worker experiences a heat stroke, he/she must receive medical attention at a hospital.

Factors in Controlling Heat Stress

Already fast-paced and dangerous environments, industrial workspaces have a number of factors that make temperature control a difficult problem to tackle. For example, most loading docks are not air conditioned and, even if they are, the combination of high ceilings in the staging areas and frequently open doors make them hard to keep cool.

The increasingly hot weather patterns in the U.S. and the rapid expansion of online retailing are two other factors that only worsen the problem. Most U.S. states have seen average summer temperatures rise in the last decade, and scientists expect the trend to continue. Additionally, as online retailing has become even more pervasive, so has the demand for overnight shipping, pushing fulfillment operations and their employees to work faster than ever.

The Basics of Heat Stroke Prevention

Facility management can help prevent heat stroke in a number of ways. Water breaks should be encouraged and employees who have not previously worked in warm environments should be given time to acclimate. They should also be reminded to self-evaluate, as heat stroke warning signs are often overlooked by the victim. Those who display symptoms of heat stress should be moved to a cooler area and monitored, and anyone suffering from a heat stroke should immediately be taken to the hospital.

Temperature Control is Lawsuit Prevention

Uncomfortably hot facilities not only lower employee morale but also make them less efficient. Mental errors are more likely to occur when overheating causes an employee’s body to pump more blood to the skin in an attempt to cool itself off, leaving less blood available for vital organs like the brain. According to a study released by the National Bureau for Economic Research published by the Washington Post, economic productivity decreases by nearly two percent for every 1.8 degrees Fahrenheit (1 degree Celsius) above 59 degrees Fahrenheit.

OSHA does not have specific regulations for indoor workplace temperatures, but the agency recommends a temperature range between 68 and 76 degrees. 28 states have adopted OSHA-approved plans for compliance with and enforcement of heat illness prevention plans. Failure to comply with these regulations can result in fines and/or a lawsuit if workers become injured as a result of heat illness.

From an infrastructure standpoint, there are a number of facility upgrades that can have an immediate impact, preventing both employee illness and potential legal action, such as upgrading dock seals, implementing fabric curtain walls, installing fabric duct work and using HVLS fans to circulate air.

Using HVLS Fans to Control Heat

While adding air conditioning is the best-case scenario, it isn’t always practical due to cost considerations and building configurations. With or without air-conditioning, though, most heat stress-prone facilities will benefit immensely from HVLS fans.

Although smaller, floor-mounted fans can be helpful in limited spaces, their high wind speed and noise levels may cause problems. They also use a relatively high amount of electricity. HVLS fans, on the other hand, use relatively little energy and provide a gentle, quiet breeze that is very comforting to workers. According to ASHRAE calculations, studies have shown that the use of an HVLS fan in combination with an air conditioning system can decrease the effective temperature between 10 and 15 degrees Fahrenheit without lowering the thermostat. A similar cooling effect occurs in facilities that don’t have air conditioning systems.

A technically advanced HVLS fan can move large volumes of air up to 31,000 square feet and replace as many as 10 to 20 floor fans. By mixing air, HVLS fans also help air-conditioning systems work more efficiently, allowing them to be operated at a set point up to four degrees higher.

Enhancing Air Flow with Fabric Ductwork

Fabric ductwork/diffuser systems use air-porous and/or strategic vents to diffuse air evenly across the entire length of the ductwork system. This full-length diffusion eliminates the hot and cold spots created by localized diffusers in traditional metal ductwork systems, which may be placed many feet apart. Conventional metal systems with high-volume diffusers also suffer significant performance differences from heating to cooling, due to buoyancy and volume changes.

Fabric duct systems are also a relatively low-cost option as compared to traditional metal systems. The light weight and flexibility of their fabric makes them easier (and therefore, less expensive) to ship than metal ductwork, as well as less time-intensive to install. They’re also easy to clean and can offer 360 degrees of air dispersion, allowing for more efficient cooling of a space.

Cordoning Off Cool Air

Industrial curtain walls are another cost-effective and flexible solution for keeping air-conditioned areas cool. Traditional rigid walls can be expensive and time-consuming to construct, creating costly downtime and inefficiencies in workflow. Fabric curtain walls provide a lower cost alternative, easily installed and moved for the needs of a workspace. Some are even specially designed to separate temperature variances as great as 40 degrees Fahrenheit.

Fabric curtain walls can be hung snugly from the ceiling, dividing air-conditioned areas from non-air-conditioned areas. Individual curtain panels of any length can be attached together using hook and loop fasteners, making a continuous barrier with massive flexibility. They can be reconfigured or maneuvered as often as desired, offering boundless possibilities for modifying room layouts should workflow and floorspace need change. They also prevent the movement of smoke, fumes, particles and noise, making the workspace an overall more pleasant and safe area.

Sealing the Perimeter with a System of Products

The loading dock presents the greatest opportunity for the loss of temperature control. Any open dock station will allow conditioned air to leave and outdoor humidity to enter. Even when trailers are snugly secured to a loading dock, small 1- to 2-inch gaps often exist between the trailer and the edges of the dock opening that equate to a 2.5-square-foot hole at just a single dock opening. Getting a consistent, gap-free seal along trailer sides, tops and corners, as well as at the bottom of dock door openings is essential to creating an environmentally secure and energy efficient dock.

Dock shelter head curtains that utilize weight and gravity help seal gaps and create a seal at the top of the trailer. On the sides of the trailer, hooks on the shelter side curtains can keep exposed hinge gaps completely covered. Gaps below and around the loading dock leveler and dock bumpers present another challenge for energy loss, but they can be covered with an under-leveler seal and/or a combination of lip corner seals, filler pads and other components to help retain conditioned air inside and warm air from entering.

Creating a Comfortable Environment

As the hot summer months bear down and shipping demand only increases the work pace, ignoring problems of excessive heat will become untenable. Working in excessively hot industrial spaces leads to employee health risks and preventable errors that every facility manager should take steps to avoid. While global factors such as e-commerce and climate change make the problem of heat stress increasingly daunting, these simple and cost-effective options can protect organizations from legal troubles, costly accidents and promote a cool, comfortable work environment.

This article originally appeared in the June 1, 2021 issue of Occupational Health & Safety.