Dehydration is a hidden threat to safety

When we talk about summer safety in the waste industry, the immediate concern is often heatstroke, and while it’s definitely a huge concern, there’s a subtle, more pervasive threat to worker safety—dehydration-related fatigue and mental fog.

Waste collection is a physically demanding job, often performed under intense heat and tight schedules. It’s easy to assume that water breaks are enough. But current science, and what we’re seeing firsthand, shows that inadequate hydration doesn’t just cause cramps and overheating. It threatens a worker’s focus, slows their reaction time and sharply impairs their ability to make quick, sound decisions. In other words, dehydration is a major contributing factor to accidents on the job, and not just in the summer, but year-round.

Hydration and cognitive function

Even mild dehydration—just a 1-2 percent loss in body water—can negatively impact cognitive performance. According to a review published in the ACSM’s Health & Fitness Journal, tasks involving attention, memory and mood are particularly vulnerable to fluid deficits at levels commonly experienced during a typical workday. The research emphasizes that these seemingly small losses can impair mental sharpness and decision-making, even in healthy adults.

A study in the British Journal of Nutrition further demonstrated that dehydration slows decision-making, especially in high-heat, high-stress environments. That means a dehydrated driver may miss a hazard, delay a reaction, or misjudge distance which are all split-second choices that can prevent or cause an accident.

In industries like waste management, where large machinery, narrow streets and irregular loads are part of the daily grind, mental clarity isn’t a luxury. It can be a matter of life or death.

What hydration really means

It’s a common misconception that hydration is just about drinking enough water. The truth is, when we sweat, particularly in extreme heat, we lose electrolytes that are critical for nerve function, muscle contractions and cognitive performance. Sodium, potassium and magnesium aren’t an added bonus—they’re essential for hydration at the cellular level.

The problem is that your average sports drink or salt packet may not cut it for industrial workers with high sweat rates and long shifts. A study from the Journal of the International Society of Sports Nutrition emphasized that optimal hydration requires both water and the proper balance of electrolytes. Without both, the body’s cooling system, muscle function and mental performance begin to degrade, and can do so before thirst even kicks in.

And let’s not forget pre-shift hydration. Many workers start their day already mildly dehydrated, especially if they’ve had caffeine, alcohol or limited fluid intake the night before. Encouraging workers to hydrate before they even clock in can make a world of difference in their performance and safety.

The hidden risk behind accidents

Over the years, the waste and recycling industry has come a long way in cutting down on preventable injuries. High-visibility gear, better vehicle safety tech and solid training programs have made a significant difference, but there’s one risk that isn’t talked enough about: the mental and physical fatigue that comes from being underhydrated.

Drivers who are mildly dehydrated may:

• zone out during longer hauls or on repetitive routes;
• react slower to unexpected hazards;
• miscalculate distances while backing up or making tight turns; or
• struggle with decision-making under pressure.

And let’s be clear, this isn’t about being careless or negligent. It’s what happens when your body and brain are running on empty.

Even more concerning, mild dehydration can mimic the effects of sleep deprivation. It can lead to irritability, poor communication and drag down morale—not exactly what you want when solid teamwork and clear communication are key to staying safe.

A real call to action for the summer season

With the heat cranking up, it’s time to start looking at hydration differently. Not just as a way to avoid heatstroke, but as a crucial part of our overall safety game plan. There are a few simple, practical steps supervisors and safety managers can take to make a real impact:

• Educate workers to spot the early signs of dehydration, like feeling wiped out, getting a headache or losing focus—not just feeling thirsty.
• Encourage sipping water throughout the day, not just chugging it during breaks.
• Offer high-quality hydration options that replace key electrolytes lost through sweat.
• Monitor workers more closely during heatwaves and on high-exertion routes.
• Recommend workers begin hydrating before their shifts even begin.

Small cues like adding a quick reminder during pre-shift safety talks—for instance, “Hey, grab some water before you head out”—can really build good habits over time. It’s a small change that can help keep everyone sharp, safe and performing their best all season long.

Hydration myths that could be hurting your team

Here’s a few common myths about hydration that might be putting your crew at risk:

• “If I’m not thirsty, I’m fine.” False. Thirst is actually a late warning sign. By the time you feel thirsty, chances are you’re already dehydrated.
• “Energy drinks count as hydration.” No. Most energy drinks are loaded with caffeine and sugar, both of which can actually increase fluid loss.
• “Water is enough.” In high-sweat environments, electrolytes like sodium, potassium and magnesium are just as important as fluids for proper hydration.

Safety in waste management has always been about more than just gear and checklists. It’s about real people doing tough, physical work under tough conditions. In the summer, that means going beyond just handing out water bottles or checking the forecast. It means understanding things like clear thinking, quick reflexes and smart decisions start with staying properly hydrated.

By making hydration a core part of our safety culture, we’re not just helping to prevent heat-related illnesses, we’re building a workforce that’s sharper, stronger and better prepared to tackle the job, no matter how high the temperatures climb.

Jim Olson has over 30 years of professional leadership, safety and environmental experience, including 24 years at Republic Services. He works as an expert witness and as an advisory board member for several organizations. Mark Paulsen is the founder of nutritional supplements company Wilderness Athlete and a strength and conditioning coach with careers as University of South Carolina, Long Beach State University and the University of New Mexico.