Heat on the farm: Keeping workers safe

by Tamara Scully

For many, farm work means long days in the field. Whether harvesting, planting, plowing, sowing, moving livestock, spreading manure or fixing fencing, farmworkers tend to spend time outdoors, no matter the weather.

Weather with elevated temperatures or humidity levels can cause illness and death to those doing outdoor work if proper precautions are not taken and symptoms are not recognized.

Farmworkers are injured or die from heat-related issues at a much higher rate than the non-farming population, as per statistics from the Centers for Disease Control. Most of the workers suffering heat-related fatalities fall into a younger demographic (20 – 54 years old) than non-farmworkers who suffer heat-related deaths.

According to an American Public Health Association report, “In the U.S., an average of 658 people died per year from 1999 to 2009 due to exposure to excessive natural heat. Crop workers, who are more likely to be young adults and reside in Southwestern states, are at higher risk of heat-related death or illness. Crop workers are more likely to be non-U.S. citizens.”

While hotter states with large farming operations, migrant worker pools and high temperatures may have more incidents of heat-related illness and fatalities, climate change is a factor in increasing heat-related incidents. Those not accustomed to working in extreme conditions have more difficulty than those who have acclimated to such weather.

According to OSHA, “Most outdoor fatalities (50% to 70%) occur in the first few days of working in warm or hot environments because the body needs to build a tolerance to the heat gradually over time. The process of building tolerance is called heat acclimatization. Lack of acclimatization represents a major risk factor for fatal outcomes.”

The risk of suffering from a heat-related illness increases with humidity and temperature levels, a lack of shade, dry wind, physical exertion, type of clothing and the use of PPE. Other factors, such as consuming caffeine or alcohol, the use of certain medications, age, underlying health conditions and water intake, all play a role in the risk of heat-related illness and death.

Heat-Related Conditions

The heat index is an indicator of how hot it feels when ambient temperature and relative humidity levels are combined. As temperatures climb, lower relative humidity levels – as low as 65% at 100º F – can cause extremely dangerous conditions, increasing the likelihood that heat-related deaths will occur. The threat gets worse as humidity levels increase. At a less extreme temperature of 90º, extreme danger levels are not reached until the humidity level climbs to 95% relative humidity.

If the heat index is at 91º or above, moderate precautions should be taken. At a heat index of 103º, the risk rises, and extra steps to ensure worker safety are in order. The most severe risk occurs when the heat index is above 115º.

But the heat index is only a guideline. As per the National Weather Service, “Since heat index values were devised for shady, light wind conditions, exposure to full sunshine can increase heat index values by up to 15º F. Also, strong winds, particularly with very hot, dry air, can be extremely hazardous.”

Since so much farm work is done in open fields, with no shade, the heat index doesn’t accurately portray the threat. If workers are without immediate and regular access to water, aren’t wearing loose-fitting, light-colored and lightweight clothing with long sleeves and wide-brimmed hats – all of which offer the best protection from the sun and intense heat – or do not have access to shade for breaks as needed, the risk of heat-related illness and death increases. For those needing to wear PPE, the risk is greater. Limiting the amount of time they’re in the sun and scheduling such tasks for cooler parts of the day greatly reduce risk levels.

In order of increasing severity, heat-related illnesses include heat rash, heat syncope, heat cramps, heat exhaustion and heat stroke. Symptoms of heat rash are prickly red bumps that itch. Wearing loose clothing and keeping skin dry are preventative measures. Heat syncope is fainting caused by heat exposure, causing blood to pool. Rest in a shady area and adequate hydration can prevent or relieve symptoms. Muscle spasms in the arms, legs or abdomen (heat cramps) can be prevented and relieved by drinking adequate water and resting in a shady area, and are caused by an imbalance in sodium. Heat exhaustion is characterized by profuse sweating, fatigue, dizziness, nausea, moist skin, paleness, chills and an elevated pulse rate. The excessive loss of fluids and a resulting salt imbalance after perspiring at a faster rate than fluid intake causes heat exhaustion to occur. Fluids, rest in the shade and cessation of work for the day are required. Those suffering from heat exhaustion need to be monitored and seen by a medical professional.

Heat stroke can be deadly and is an immediate emergency. Symptoms include confusion, seizures, fainting, dry skin (which can be red in color), high body temperature and a rapid pulse rate. Breathing becomes shallow. The central nervous system can no longer regulate body temperature, and sweating shuts down. Body temperature rapidly rises. Call for emergency services immediately, move the person to shade and cool them down by fanning them and cooling their clothing with water.

Training & Safety Plan

Water intake is very important in preventing heat-related illnesses. Drinking eight ounces of water every 15 minutes is recommended when working in the heat, whether feeling thirsty or not. Avoid caffeine or alcohol before and during work activity. Frequent, brief cooling down breaks, taken in a shady area, should be encouraged to prevent early symptoms of heat stress from becoming more serious. All workers should be trained to monitor themselves and others for symptoms of distress.

Workers that are new to the job need to acclimate to weather conditions. Weather conditions that rapidly changed from cooler days to extreme heat don’t allow anyone to acclimate, and even seasoned workers need to adjust gradually in those circumstances.

Workers who take medications may be at increased risk for heat-related illnesses, and should discuss this possibility with their physicians as well as alert their employers.

OSHA offers downloadable heat safety cards. These can be easily provided to workers to help prevent, identify and treat heat-related illnesses.

Environmental heat and metabolic heat (created by the body as it works) combine to contribute to heat-related illnesses. Heavy workloads make it much more likely that heat stress can occur, even during conditions which are low risk per the heat index. Intense upper body work, such as carrying or moving hay bales or feed, sawing wood, shoveling or pushing or pulling loads, carries a higher risk of heat-related illness.

For farmworkers, these types of activities are regular parts of the job, performed in all types of weather. Being mindful of conditions which increase the risk of illness and death due to heat stress, taking steps to prevent them from occurring, knowing the symptoms and having emergency plans in place to treat heat-related illnesses is a necessity for all farm operations.

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