How to Work Safely in the Earth’s Rising Temperatures

When working in the heat, taking the right steps to ensure safety is essential.

• By Ryan Butler
• Jun 01, 2022

As industrial workforces await OSHA heat standards, it’s important to get safety managers and workers up to speed on heat safety. It’s an issue that’s been around for decades, and dangerous heat now kills more Americans than any other weather-related event, but it’s only recently starting to get more attention.  

Understanding heat safety starts with understanding basic heat stress physiology. The body wants to maintain its temperature where it’s most comfortable and works most efficiently. This temperature is typically around 97.9 to 98.8 degrees Fahrenheit (about 36.6 to 37.1 degrees Celsius). The two main ways the body keeps itself in this narrow range is through shivering to increase heat production or losing heat through an increase in sweating and blood flow to the skin.  

Proper Acclimatization is Step One  

Most heat-related deaths and injuries occur in the first few days on the job. Heat acclimatization can help prevent this. Heat acclimatization is a process where your body undergoes physiological changes that allow it to better handle the heat—which means that your performance in the heat will improve and you are less likely to suffer from heat-related problems. Getting properly acclimatized to intense heat is different for everyone, but the principles are the same—to ease into it. Spending too much time in the heat early on is a recipe for disaster, so increase that time during the first one to two weeks of work. 

If working in an environment with heavy equipment or PPE, start with minimal clothing and work up to full PPE. If possible, start by wearing the most minimal clothing layer on the first one to two days of heat exposure, and then slowly add each additional clothing layer (every one to two days) to give the body time to adjust during the acclimatization period.  

Remember, don’t push too hard in the first week. After acclimatization, there will be some noticeable physiological changes. Sweat rate will increase, allowing your body to better cool itself. In addition, your heart rate will be lower and core/skin temperature will be lower because your body is staying cooler.  

Some research suggests that men and women respond differently to heat acclimatization. Women have lower sweat rates and are more frequently diagnosed as heat intolerant compared to males, suggesting that men might adapt faster (acclimatize quicker than women) to the heat.  

There are a few other explanations for gender-affecting heat acclimatization. One is the differing thermal loads in men and women. Being in the heat may be providing a greater heat stimulus to males than to females, which allows for faster adaptation. Men have more muscle mass than women, even at the same weight. This means that performing similar tasks causes more muscular activity in men, and therefore more heat production. Additionally, the average man is larger and heavier than the average woman, which explains why men produce more heat in their muscles. 

So—since it seems men produce more heat while working in hot weather, which leads to quicker acclimatization—how can industrial workforces accommodate for their female workers? One practical solution is to add additional layers of clothing early on during the acclimatization process for women. These additional layers cause a larger thermal load, allowing female workers to produce heat more similar to their male counterparts. It’s vital to monitor female workers more carefully during this process as well, since most of the research in this area has been conducted on young males. Wearing heart rate monitors and conducting “check-ups” throughout the workday are some ways to keep track of your female workers’ development towards full heat acclimatization.  

Despite the physiological differences in men and women, there are general recommendations to avoiding heat injury that stay the same for both genders. Since each worker has unique physiology and reacts to the heat differently, these rules apply to everyone.  

Hydration is Imperative 

Hydrating is one of the best ways to keep productivity high and minimize dangerous increases in core temperature. Some easy ways to stay hydrated include drinking a glass of water when waking up in the morning, carrying a water bottle throughout the day as a reminder to hydrate, and by not limiting water intake by only drinking when thirsty. Checking urine color is the easiest way to determine if you’re properly hydrated. Research also suggests that urinating seven times per day is proof that you’re hydrated, while less than five times per day shows dehydration.  

When dehydrated, you won’t be able to complete as much work, your body temperature will go up faster, you will be more fatigued and cognition may be impaired. Hydration starts on a personal level, but it’s also important to have water available in multiple locations at the worksite.  

Know When to Work and Rest 

Another crucial step in minimizing the risk for heat injuries and illnesses is to develop a proper work/rest schedule depending on all environmental conditions. Some work/rest schedules only account for temperature and humidity but don’t incorporate other variables at the worksite, such as radiant heat or workers’ clothing.  

It’s important to select a work/rest schedule that makes sense for work conditions at the site, considering all possible variables. During these rest periods, workers should actually rest without performing any other tasks. They should be provided with water and shade or air conditioning to cool down. Workers should be allowed to remove any extra clothing that might be restricting evaporative heat loss (i.e. that keeps the sweat from evaporating off their skin).  

Outside of a rest schedule, rests should also be taken for workers experiencing heat stress symptoms. In extreme situations, every worksite should have an emergency ice bath at the ready. If someone is properly cooled in an ice bath within 30 minutes after they collapse from heat exhaustion, their odds of survival are 100 percent. It’s simple—use a large tub, kiddie pool or tarp nearby a water supply and keep large coolers filled with ice next to the tub. Fill the water up to the worker’s chest and call emergency medical services if the heat stress is extreme. Make sure to keep the person’s head above the water and continuously circulate the water to make sure the coldest water is constantly surrounding the worker. If there’s no ice bath onsite, use ice packs and rotate them around the body as much as possible.   

Additional Tips 

Other good strategies to maintain productivity and maximize performance in the heat include avoiding sugary foods and drinks, as well as alcohol and drugs. Your body is being asked to perform at a high level, and poor nutrition will only impair your performance and lead to increased risk for heat injuries and illnesses. Staying fit through exercise and a healthy diet can also improve productivity and minimize risk for heat injury.  

Lastly, allow for sweating. Sweating is the main way that the body cools itself down. Try to eliminate clothing that keeps sweat from evaporating and use a towel to wipe off dripping sweat.  

Emerging climate tech is now playing a part in keeping workforces safe. There are now wearable devices being used that continuously monitor an individual’s physiology, alerting them when their core body temperature is too high or if they’re over-exerting themselves. Tech solutions are extremely effective and allow safety managers and workers to understand physiology. Tech is gaining popularity in the industrial workspace.  

It’s clear that hot environments pose significant challenges to the body. As workforces around the globe lose millions on worker injury costs and productivity loss, it’s important to recognize that heat injury and illness is 100 percent preventable. When workers are properly acclimatized to the heat, hydrated and rested, and armed with climate technology that monitors their heat risk, industrial workforces operate more efficiently. 

This article originally appeared in the June 2022 issue of Occupational Health & Safety.