Heat-related illnesses are preventable. Heat stress is brought on by prolonged overexposure to heat and the sun, causing heat exhaustion or life-threatening heat stroke, and/or exacerbating pre-existing conditions.
In a review of deaths from 1979 to 2003, extreme heat killed more people than hurricanes, floods, tornadoes, and lightning combined. As climate change progresses, which has already brought record-breaking heat to many parts of the US, deaths from heat stress are projected to grow substantially. The 2016 Climate and Health Assessment summary notes that “people working outdoors, the socially isolated and economically disadvantaged, those with chronic illnesses, as well as some communities of color, are especially vulnerable to death or illness” due to heat stress. Many agricultural workers, construction workers, truck drivers, and day laborers with whom we work fall into several of these categories, which demonstrates their compounded susceptibility to heat stress. Whether in the midst of migration, at work, or at home, migrant populations are at a higher risk for this preventable but sometimes fatal condition.
The two most serious heat-related conditions are heat exhaustion and heat stroke. Symptoms of heat exhaustion include headache, heavy sweating, a rapid pulse, intense thirst, weakness, anxiety, dizziness, or fainting. Untreated, heat exhaustion can lead to heat stroke. Heat stroke is a life-threatening medical condition that is similar to heat exhaustion, but may also feature dilated pupils, increased body temperature, confusion or loss of concentration, and/or nausea and vomiting.
There are many excellent resources for outdoor workers on heat stress, which depict the symptoms and treatment in more detail, in low-literacy or multilingual materials. Please see our
Heat Illness Resources page for a complete list of recommended materials. On the Job
Many workers die from heat-related illnesses each year, and every death is preventable. Agricultural workers, construction workers, day laborers -- all of these professions require workers to perform heavy labor often in direct sun for multiple hours. Much of the work is done during the hottest and most humid times of the year, and may require heavy protective clothing, both of which further contribute to a worker’s risk of heat stress. Additionally, indoor workers in locations like warehouses that lack air conditioning or sufficient ventilation are at risk of heat stress. Lacking sufficient training or without the ability or encouragement to take breaks, workers may not adequately respond to the dangers of heat.
New workers are especially prone to heat stress, as their bodies have not acclimated to the heat or humidity. There are unfortunately many documented incidents of workers dying during their first week of work. Of 20 cases of
reported heat deaths between 2012 and 2013, nine occurred during the worker’s first three days of work; four of those were on the worker’s first day of work. The Pacific Northwest Agricultural Safety and Health Center (PNASH) recommends new workers to begin at half time and increase work time by ten percent each day.
Agricultural workers may be particularly vulnerable. Piece workers, who are paid by the amount that they pick rather than by the hour, may be resistant to taking sufficient rest and water breaks for fear of loss of remuneration. Additionally, as the early symptoms of heat stress manifest, workers experiencing disorientation or confusion may be less able to accurately assess when they need a break.
Standards for health stress vary by industry. In agriculture there is no national heat illness standard. OSHA standards require agricultural employers to provide access to water within a quarter-mile of a worker on mid-size and large farms to workers (with smaller farms exempt in most states), but many important steps to prevent heat stress are not required on US farms. As is evidenced by the many annual heat-related deaths across the US, regulations have not been sufficient. Employers in various industries need to take steps to give access to shaded rest areas, provide sufficient water, give heat-related illness trainings to workers, and post written policies and procedures to assist workers in helping those who may be experiencing heat stress.
California and Washington each have heat illness prevention regulations that address each of these steps. Industry-specific resources are available on OSHA’s website.
Community health workers (CHWs) can provide an important bridge between the medical community and the outdoor workplace when it comes to heat stress. Migrant Clinicians Network’s
project addresses heat stress as a serious occupational hazard for agricultural workers and offers training for CHWs to assist workers in preventing heat-related illnesses. Worker Safety and Health in Community Health Centers
Employers must also be sufficiently trained on the dangers of heat stress, and provided with tools to best manage this health concern. Employers, in addition to providing shade, water, training, and posted policies, should monitor the daily
heat index and adjust work schedules accordingly. The heat index is a value that takes into account both air temperature and humidity, the latter of which can increase the danger of heat illness during the hottest and most humid months. OSHA’s campaign to prevent heat illness offers extensive resources for employers and CHWs, including a Heat Safety App that displays the work site’s estimated heat index for the day, and assigns a risk level for outdoor workers accordingly. At Home
Many underserved populations live in substandard housing that may lack air conditioning or sufficient ventilation, like many on-site camps for migrant agricultural workers. Those who experience heat stress during the day cannot recover if their housing is dangerously hot. A 2012 study that tested the heat index in common and sleeping rooms in migrant agricultural worker housing in North Carolina during the summer months found “dangerous heat [indices] in most rooms, regardless of time or air conditioning.”
While on the move, migrants may be more susceptible to heat-related illness due to the conditions of migration. Many migrants travel in cars, boats, trains, and buses that lack air conditioning or sufficient air circulation.
Hundreds of thousands of people attempt to cross the US-Mexico border each year, often walking for days through the desert. In recent years, as migrants seeking to cross the border illegally have pushed into less populated routes to avoid border control, the number of heat-related deaths has increased. Over 60 percent of deaths at the border are attributed to heat-related causes.
Migration may cause heat stress, but heat stress also causes migration. Climate change-worsened heat may be a major driver of future migration waves. A 21-year longitudinal survey conducted in rural Pakistan discovered that catastrophic weather events like major flooding did not contribute to climate migration as much as heat stress, and that heat stress “consistently increases the long-term migration of men, driven by a negative effect on farm and non-farm income.”3
References Quandt SA, Wiggins MF, Chen H, Bischoff WE, Arcury TA. Heat index in migrant farmworker housing: implications for rest and recovery from work-related heat stress. Am J Public Health. 2013;103(8):e24-6. Ruttan T, Stolz U, Jackson-vance S, Parks B, Keim SM. Validation of a temperature prediction model for heat deaths in undocumented border crossers. J Immigr Minor Health. 2013;15(2):407-14. Mueller V, Gray C, Kosec K. Heat Stress Increases Long-term Human Migration in Rural Pakistan. Nat Clim Chang. 2014;4:182-185. Resources