The estimated 2.4 million farmworkers in the United States are vital to US food production. However, these workers are exploited, undervalued, and vulnerable to compounding climate change threats. The Union of Concerned Scientists (UCS) assessed how pesticide exposure and heat stress conditions combine to present significant risks to farmworkers’ health and safety. We focused on California, Florida, and Washington—states that lead the nation in pesticide use, farmworkers, and production of labor-intensive fruits, nuts, and vegetables. We found that farmworkers in these states already experience substantial threats and that these are likely escalating. Policies to protect farmworkers’ well-being from the dangerous consequences of extreme heat and pesticides are urgently needed.