Summers on the farm can be brutal. The frequent combination of lingering drought and prolonged heat stresses crops and animals and diminishes productivity.

It can also be devasting, even deadly, to workers, including farmers and ranchers, exposed to extreme heat that can result in heat stroke, heat exhaustion, heat cramps, or heat rashes.

Agricultural workers can’t always avoid heat; essential chores remain even under triple-digit temperatures. They can take precautions, however, and reduce the potential for heat-related injury.

The Southwest Center for Agricultural Health, Injury Prevention, and Education, located at the University of Texas at Tyler Health Science Center, offers guidelines to recognize, react to and prevent heat-related injuries.

Awareness

Amanda Wickman, SW Ag Center Program Director, says being aware of the symptoms of heat illnesses is crucial. “Some very specific heat stress symptoms are easy to pass off as something else. People tend to ignore early symptoms, things like a headache or feeling lightheaded. Those are triggers to say, ‘Okay, I need to go rest. I need to go inside. I need to get water.’

“The best thing to do for heat stress is to educate people on how to spot the signs and symptoms and then to recognize serious symptoms, which are sometimes missed.

“For heat stroke, when people stop sweating and their skin is red and hot or they're confused, saying things that do not make sense, just talking nonsense, that is an emergency situation. I'm not sure that a lot of people connect mental disorientation to heat illness.” Wickman added that having a buddy system can assist with identifying heat stress symptoms in others.

Symptoms

Knowing the symptoms is crucial. Heat-related illnesses and symptoms include:

Heat Stroke

What to do:

Heat Exhaustion

What to look for:

What to do:

Get medical help right away if:

Heat Cramps

What to look for:

What to do:

Stop physical activity and move to a cool place

Heat Rash

What to look for:

What to do:

In addition to the illnesses caused by heat stress, workers may also be more prone to indirect injury. Heat may result in sweaty palms, fogged-up safety glasses, and dizziness, which may precipitate incidents and injuries.

Prevention

As with most safety concerns, prevention is the first consideration. Employers should provide training so workers understand how heat stress affects their health and safety, and how it can be prevented.

David Smith, Texas AgriLife Extension Safety Program, details key heat stress prevention measures in an Extension publication, “Coping with a Hot Work Environment.”

“Discomfort is not the only disadvantage of working in high temperatures and high humidity,” Smith says. “Individuals who work long hours in the heat or who are suddenly exposed to working in a hot environment face sometimes serious, but largely avoidable, hazards to their safety and health.”

He adds that preventing heat stress should be a shared responsibility of employer and employee.

“A person’s stress depends, in part, on the amount of heat a person’s body produces while working. More heat is produced during hard, steady work than while doing light work.”

He offers the recommendation below to lower heat stress on the job.

Smith says outdoor workers are especially subject to changes in heat and humidity. A hot spell or an unusual rise in humidity can create overly stressful conditions for a few hours or for days.

Preparation

Smith offers several work practices during these periods, including:

Setting aside a rest area in cool surroundings will reduce potential for heat stress.

“The rest area should be close to the workplace. The farther away the rest area is, the more likely that it will be used infrequently or that work periods will be lengthened between proper rest breaks. Rest is most beneficial when breaks are short but frequent. As environmental heat increases, increase the frequency and length of rest periods.”

Readily available drinking water is essential. “In the course of a day’s work in the heat, a worker may sweat away as much as 3 gallons of fluid in which vital substances are dissolved. Because so many heat disorders are caused by dehydration and loss of salt, water intake during the workday must equal the amount of sweat.”

Smith says most workers drink less than they should because they satisfy their thirst before the body’s water requirements are met. “A worker should not depend on thirst to signal when and how much to drink but should drink more than enough fluids to satisfy thirst every 15 to 20 minutes.”

He says water should be cool (50 to 60 degrees F.), palatable, and conveniently close to the work area. “Unacclimated workers lose much more salt in their sweat than workers who are acclimated to the heat, but everyone loses some. The best way to replace this is to have a 0.1 % salt solution available as drinking water. A level tablespoon of table salt dissolved in 15 quarts of water (1/4 tablespoon per gallon) will make this solution.” Salt tablets are another option but must be taken with ample water to prevent gastric irritation.

“Be extra careful during the first days of exposure to heat,” Smith cautions. “Workers should liberally salt their food and do whatever they can to replace lost salt.”

He adds a caution. “Persons with heart problems or on low sodium diets must not be given salt. Consult a physician on how to care for people with these conditions.”

Smith says an unacclimated person can sweat as much as 1 quart per hour. “However, after a few hours, sweating diminishes because of sweat gland fatigue. This occurs particularly in humid environments. The capacity for sweating varies greatly from one individual to another.”

Protective clothing

Clothing can be a factor. Smith says some types of clothing “inhibit transfer of heat between a person and the surrounding environment. In hot jobs, where air temperature is less than skin temperature, clothing reduces the body’s ability to lose heat.

“But when air temperature is higher than skin temperature, clothing helps prevent the transfer of heat from the air to the body. On the hottest of summer days, for instance, conditions may be intolerable for a worker wearing only shorts but tolerable for a worker in shirt and trousers.

“The advantage of wearing clothing is lost if the clothes interfere with evaporation of sweat. Avoid tight, closely fitted garments made of loosely woven fabrics. Loose garments made of thin cotton fabric are recommended. In dry climates, adequate evaporation of sweat is seldom a problem.”

Susceptibility

“The most susceptible to heat illness are the obese, the chronically ill, and the elderly. Adhere to preventive measures rigorously during extended hot spells and avoid any unnecessary or unusual stressful activity.”

Sufficient sleep and good nutrition are important for maintaining heat tolerance.

Reschedule tasks

Smith recommends that workers schedule the most stressful work during cooler parts of the day (early morning or at night) and extend rest periods as heat rises.

Other precautions include avoiding alcoholic beverages, which can cause additional dehydration. “Persons taking special medication should consult their physicians to determine if it could cause side effects during excessive heat exposure. Certain medications for blood pressure control and diuretics, or water pills, may also cause dehydration.

“Weigh yourself before beginning and at the end of the workday to determine weight loss from progressive dehydration. Daily fluid intake must be enough to prevent significant weight loss during the workday and over the workweek.”

Extreme heat can persist for days, even weeks in the Southwest. Heat illnesses typically increase during these extended hot spells.