Death by Degrees

The Centers for Disease Control and Prevention report that heat-related deaths are on the rise. The workers most affected by this lethal trend–by an alarming margin–are farmworkers. According to the CDC, agricultural workers die from heat stroke at a rate not double or triple or even quadruple the rate of other workers, but 20 times greater than the general US workforce.

The reasons go beyond the obvious fact that farmworkers are in an open field, under the sun, most of the day. In addition to environmental heat, the human body also generates heat internally with every exercise of a muscle. And when farmworkers are paid by how much they harvest, rather than by the hour, they are financially incented to maximize physical exertion in order to fill more buckets of sweet potatoes or blueberries or whatever. The harder they work the more they earn. Limited access to shade, or the need to walk long distances to get to it, only heightens this effect.

The human body has mechanisms for shedding excessive heat. But even these can give out under the extreme conditions of farmworking. We produce sweat in order for it to evaporate, thus transferring heat from skin to air. But the sweat can’t evaporate when the farmworker is clad head-to-toe in the heavy, long-sleeved clothing needed to keep toxic pesticides from entering that same skin. Even when we can sweat freely, that sweat takes precious salt from our bodies, causing water to rush into muscles, leading to painful cramps or spasms. Worse, redirection of blood to the skin reduces blood flow—and hence oxygen—to the brain. This leads to symptoms such lightheadedness, dizziness, irritability and impaired judgment.

Once our body temperature exceeds 104 degrees, our heat regulators all but give up. The sweating stops. And this is like a nuclear reactor losing its coolant. The core can no longer function properly and organs such as the heart, liver and kidneys can start to fail. So too the brain and the central nervous system. Left in this state, it’s only a matter of time before the convulsions and seizures set in, then coma and brain damage, and ultimately death.

Nobody knows how many farmworkers have suffered this fate. And the ill effects of heat don’t end with the work day. A 2012 study in the American Journal of Public Health shows that farmworkers continue to experience excessive heat even after leaving the fields.

Even one heat-related death is too many because we know how to prevent them. The CDC, in collaboration with the National Institute for Occupational Safety and Health, has published an employers guide for preventing heat-related illness or death.

The extraordinary risk of heat-related death is but one of many reasons agricultural work is among the most deadly occupations in America. And with extreme heat events on the rise, the need to address this risk is more urgent than ever.


A version of this essay first appeared on Farmworker Advocacy Network blog on July 2, 2013


Get used to killer heat waves, CDC warns

CDC urges everyone: Get ready to stay cool before temperatures soar

Preventing Heat-related Illness or Death of Outdoor Workers

Heat-Related Deaths Among Crop Workers — United States, 1992–2006

Farmworkers continue to experience excessive heat even after leaving the fields, shows research