Heat and the human machine

If you have thirst, your body's preparing for the worst.

Our bodies have thousands of components working together to keep us alive. If you compare it to a machine, it’s easier to understand how the body reacts to outside forces such as disease and the elements.

Like a well-designed piece of equipment, the human body works to maintain a constant temperature as it is exposed to an ever-changing environment.

Temperature, humidity, radiant heat (which can come from the sun or work equipment) and air velocity influence the stress a worker faces in a hot work area.

To keep body temperature within safe limits, the body must get rid of excess heat. It does this by varying the rate and amount of blood circulating through the skin and by sweating.

These automatic responses usually occur when body temperature exceeds 98.6 F. To lower body temperature, the heart pumps more blood to expand blood vessels. The microscopic blood vessels (capillaries), which thread through the upper layers of the skin, radiate excess heat into the atmosphere.

If air temperature is as warm as or warmer than the skin, blood brought to the body surface cannot lose heat. Under these conditions, sweat glands pour liquids containing electrolytes onto the surface of the skin, which evaporate. It becomes the primary way the body maintains its temperature.

Sweating does not cool the body unless the moisture can evaporate. On humid days, evaporation decreases so the body is less efficient at cooling.

Strength declines and fatigue comes on faster. Alertness and mental capacity may be affected, so workers who perform delicate or detailed work may find their accuracy suffers. Comprehension and memory may also suffer.

Heat-related health problems
“In an average year, over 175 Americans die of heat stroke,” says Rick Smith of the National Weather Service’s Southern Region located near Dallas, Texas. “That’s more than tornadoes or hurricanes. Heat is kind of a silent killer because deaths occur very slowly and over several months during the summer.”

Excessive heat exposure can cause a variety of heat-induced disorders. Heat stroke, the most serious of heat-related injuries, occurs when the body’s temperature regulatory system fails. As body temperature climbs above 105 F, victims become confused, delirious and even unconscious. Without fast treatment, they may die.

Workers can also suffer less-severe effects in high-heat situations. The most common are fainting, transient heat fatigue, heat rash and cramps.

Heat cramps occur when a person sweats profusely and drinks lots of water but does not adequately replace the electrolyte lost through perspiration.

Drinking large quantities of water to quench thirst can dilute the body’s fluids while the body continues to lose vital mineral salts through perspiration. When the salt level falls low enough, it induces painful muscle cramps. The most tired muscles are the most susceptible to cramps. Cramps may occur at work or after an employee completes his or her shift.

Electrolytes are a key part of keeping our bodies functioning properly. The body needs them in two forms: simple inorganic salts of magnesium, potassium, sodium or calcium, or in complex organic molecules. Ideally, electrolytes flow through muscle cells to keep them functioning normally.

However, in heat-stress situations, precious minerals are lost through perspiration or other forms of dehydration, which depletes fluids from the muscle cells and weakens muscle tissue.

While drinking water rehydrates the body, it does not effectively and quickly replace the electrolytes. This can lead to safety hazards and situations where workers are much more prone to injuries.

Refuel with electrolyte replacement drinks
Today, many companies have gone beyond keeping cool liquids and water on hand for employees to drink. They also offer the rejuvenating power of electrolyte-replacement drinks.

“In my spare time, I race mountain bikes semi-professionally,” said Jeff Diamond, tank wash manager of Schneider Bulk Carriers, “I have experienced firsthand what the rapid loss of electrolytes can do. I don’t want that to happen to my workers when they’re on the job, so we encourage them to drink electrolyte replacement drinks in heat-stress situations.

“I’ve noticed that it keeps productivity from declining and improves concentration. It has definitely reduced careless injuries, such as slips and falls, that could normally be attributed to the heat,” he says.

Tonya Blakely, human resource manager at J.J. Ferguson Sand & Gravel, Inc., also believes in electrolyte-replacement drinks. “The asphalt we pour is right at 300 F. When you look at that with a heat index of 110F to 115 F, water just doesn’t give workers what they need to keep going. We we provide them with Sqwincher and find workers suffer from heat stress only when they either don’t drink the product or don’t drink enough of it.”

Electrolyte replacement drinks such as Sqwincher are an economical alternative to the costly effects of on-the-job heat-stress injuries.

“For pennies an ounce, I can decrease heat-related safety hazards and keep our workers’ energy level up,” says Diamond. “Plus, everyone likes the taste so they drink more of it.”

Electrolyte replacement drinks vs. water
While water still reigns as Mother Nature’s perfect drink, it takes a back seat to electrolyte-replacement beverages in high-heat situations. Research shows that water is absorbed much more slowly and cannot be retained in the extra-cellular cavity. In fact, the rate of absorption of electrolyte-replacement products when compared with water is 98 percent faster in the first minute.

“I like to use the radiator analogy,” says Diamond. “You wouldn’t just add water to your cooling system, you need a specially formulated coolant that’s designed to keep your engine from overheating. Electrolyte-replacement drinks are specifically designed to work in our bodies much the same way.”

While many companies spend thousands of dollars on heat-reducing equipment, electrolyte-replacement drinks can be the most cost-effective heat-stress prevention option.

Averaging only pennies per ounce, these revitalizing liquids reduce heat stress and heat-related injuries and increase productivity and promote a more pleasant work environment. In the long run, adding electrolyte replacement drinks to your heat-stress prevention arsenal could be a wise investment.

Published in the May/June 2001 issue of Contractor Tools and Supplies magazine.

back to top