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By Diane M. Calabrese / Published June 2017
It’s not always easy to stay alert when the weather is hot. (In fact, ‘hot’ derives from the same word as fever, a definite distraction.) In some instances, it may simply be too hot to work outdoors. Situational awareness is important. Knowing the basics of what can be a liability in hot weather reduces risk all around.
The Occupational Safety and Health Administration (OSHA) and other government entities emphasize the warning signs of heat-related health disorders. Most of us know how to recognize and take first aid action in the event of heat cramps, heat exhaustion, and heat stroke.
Preventing the body from succumbing to heat-induced conditions is a universal safety goal. Be sure to include among the ‘conditions’ an impairment of judgement that makes using machinery or working high less safe. Our natural way of cooling is to perspire. The water loss across our skin cools us, but the water must be replaced.
“Drink water even if you are not thirsty,” says Randy Wahl, owner of Advantis Pressure Washing in Sarasota, FL. As someone who works in hot weather most months of the year, he knows staying hydrated is a requisite to safety in hot weather.
The general recommendation is to drink small amounts of water frequently. Taking on a big stomach-load of fluid will only add to discomfort. Another Sunshine State contractor echoes and expands on Wahl’s advice. “Hydrate,” says Ray Burke owner of Spray Wash Exterior Cleaning LLC in Tallahassee, FL. “Don’t overdo it. If you feel you need a break, then take one.”
There’s no way to overstate the importance of hydrating, and Burke puts an exclamation on it. “Hydrate!” he says. “We’ve also bought ‘cool towels’ for the employees to wear.”
It’s never been necessary to stop work for a day because it was so hot, says Burke. But he did have an employee “pass out while cleaning a football stadium—turns out he was not hydrating.”
Burke gains in safety from the expertise among his workers. “We employ firemen who have paramedic certifications on our team, so it’s nice to have that extra level of safety and medical attention should bad things happen when you’re at work,” he explains.
To be sure, taking care to keep all safe is what carries the day. Special attention is required and given in hot weather. Those who work in hot weather year-round know how to factor in heat. “We’re all Florida boys at this company, so heat is the normal thing for us,” says Burke. “The biggest challenge for us in hot weather is the rapid pace at which water and cleaning solutions evaporate. It makes you change your cleaning plan and adjust to the temperatures.”
Considered a disorganized form of energy, heat nevertheless causes a multitude of safety issues. Its direct toll on the human body is just one. Because heat transfer occurs from a higher temperature point to a lower temperature point, burns happen. Not only are those working in hot weather subject to radiant heat, they may also be exposed to the effects of conduction. Touch a piece of metal that has been in direct summer sun and it could mean a burn.
When working in a parking garage or a relatively enclosed part of an urban area, a contractor may experience a micro-scale heat island effect, or the build-up of heat because several conditions overlap: Air is warm because of summer sun. Pavement and building exteriors are emitting radiant heat. Circulation of air is poor.
Heat islands, whether city-wide or localized (micro-scale), tend to concentrate pollutants. Engine emissions do not disperse as quickly, for example. Hot conditions, then, can expose workers to more than the heat itself. Working in hot weather in personal protective equipment (PPE) becomes more difficult, yet the PPE applicable to the job must be worn.
Radiant and conductive heat also affect the performance of machines. Be sure to use equipment within the tolerances recommended by the manufacturer. In hot weather, the schedule for routine maintenance is likely to change. Know what it is and follow it.
Convective heat, or that which transfers through a liquid, may also be an issue in hot weather. If carrying chemicals or coatings, shelter the containers and use only within the prescribed temperature range.
High humidity can make heat more oppressive. When the air is laden with moisture, convective heat may add to the effect of radiant heat because water molecules in the atmosphere retain and convey heat. The ‘heat index’ that meteorologists give us takes into account both heat and humidity.
When the air is so hot and full of moisture that perspiration accumulates on the skin (instead of evaporating), the core heat of the human body begins to increase. With the retention of water, the salt balance of the body changes. Muscles may react by not relaxing fully after a contraction (i.e., cramping).
Heat cramps signal the need to rest, get into the shade, and re-equilibrate. Not cooling down can lead to heat exhaustion, a mild form of shock. The exhaustion occurs because to compensate for high core temperature, blood flow to the skin increases (vessels dilate) and blood flow to organs decreases. (The body is trying to right itself by reducing core temperature.) If heat exhaustion is not addressed by rest, cooling, and measured fluid intake, heat stroke may occur. Heat stroke can cause brain damage and death.
Fitness is a factor in the ability to work in hot weather. Generally, the more fit an individual is, the greater his or her surface area to volume ratio will be. The more surface area a body has per unit volume, the more successfully heat can be dissipated. (Carrying a lot of extra weight puts us more in the category of a beach ball than beach mat. The mat has more area across which to release core heat.)
Not everything is more difficult in hot weather. No one need worry about slipping on ice, for example. But insects, arthropod-transmitted bacteria (e.g. Lyme, Rocky Mountain spotted fever) and viruses (West Nile, Zika), and poisonous plants compound the direct threat of hot weather.
Bees and wasps may be extremely aggressive. Not only do they sting, but some bees, such as carpenter bees, will bite (using their mandibles). For certain individuals, encounters can be lethal. Those who know they have a severe reaction may carry epinephrine that they can inject to combat anaphylactic shock. Any first aid kit should have at a minimum a quick-acting, strong allergy medication, which can be taken to combat to some degree a serious reaction to a sting or bite.
The CDC (Centers for Disease Control and Prevention) ranks bees as the deadliest animals in the United States. In Australia, bees kill more people each year than do snakes. How many people are killed by bees (and wasps)? That’s a bit difficult to say. In our nation, it’s at least 100 (or more than five times the number dying from heat stroke). The problem with estimates is that deaths often are attributed to a different cause, such as heat stroke, because the initial sting or bite was not recognized and there is a misdiagnosis. And a bite or sting can lead to an infection that causes death.
Light-colored clothing and insect repellent help reduce exposure to arthropods (including insects) that transmit diseases. (Light-colored clothing also helps a bit in deterring bees and wasps.) Good coverage from clothing protects against exposure to disease vectors and makes a barrier to sap from poisonous plants. If skin does come in contact with a poison ivy, oak, or sumac plant, rubbing alcohol applied immediately may reduce the likelihood of a reaction.
Shower as soon as possible after completing a work day to remove any insect repellent. Wash clothes to get rid of ticks or the like that rode along home.
Finally, there’s the sun itself. Summer sun presents a greater risk of exposure to ultraviolet radiation (UV). Limiting exposure to the sun lowers the risk of skin cancer, as well as wrinkles. Limiting exposure includes wearing a hat. Wearing sunglasses reduces the likelihood of cataracts later in life.
Contractors working outdoors deal with the most direct effects of hot weather. Distributors and manufacturers should also review hot-weather safety with their employees because heat build-up in service bays or in manufacturing lines in plants without air conditioning (rare) also subject employees to risk.
Tip sheets that can be posted for employees can be easily found on the Web. See OSHA (www.osha.gov). One candid illustration of what can happen to an overheated person is illustrated by the OSHA publication titled “Water. Rest. Shade.” The document (www.osha.gov/SLTC/heatillness/index.html?utm_source=Twitter) does get the point across, albeit in a very graphic way.
Be prudent. Stay safe. Enjoy summer.