biostudies-literatureUnknownZhou W<h4>Background</h4>While high temperatures are linked to poor sleep, few studies considered heat stress, especially among outdoor workers.<h4>Objective</h4>We investigated associations between heat stress and sleep health among farmers.<h4>Methods</h4>The study included 8,203 male participants from Iowa (78%) and North Carolina (NC, 22%), enrolled in the Agricultural Health Study (2013-2015), who were actively farming when data were collected. Survey data on sleep, demographics and covariates were linked to daily wet bulb globe temperatures (WBGT) from May 2013-September 2015. We calculated absolute heat stress by averaging WBGT over 2, 5, and 7 days before the interview. Relative heat stress (i.e., the difference between absolute heat stress and the 92.5th percentile of WBGT) was also calmedRxiv : the preprint server for health sciences2025.07.28.25332331https://www.ebi.ac.uk/biostudies/studies/S-EPMC12324656biostudies-literatureHeat Stress in relation to Sleep Health among Farmers.PMC12324656Parks CGJackson CLOgbenna BTZhou WSandler DPGaston SAfalseHeat Stress in relation to Sleep Health among Farmers.<h4>Background</h4>While high temperatures are linked to poor sleep, few studies considered heat stress, especially among outdoor workers.<h4>Objective</h4>We investigated associations between heat stress and sleep health among farmers.<h4>Methods</h4>The study included 8,203 male participants from Iowa (78%) and North Carolina (NC, 22%), enrolled in the Agricultural Health Study (2013-2015), who were actively farming when data were collected. Survey data on sleep, demographics and covariates were linked to daily wet bulb globe temperatures (WBGT) from May 2013-September 2015. We calculated absolute heat stress by averaging WBGT over 2, 5, and 7 days before the interview. Relative heat stress (i.e., the difference between absolute heat stress and the 92.5th percentile of WBGT) was also cal2025-01-01T00:00:00Z2025 Jul2026-04-07T14:20:11.636Z2026-04-07T14:01:10.173ZS-EPMC123246564076614310.1101/2025.07.28.25332331