Heat exposure from tropical deforestation decreases cognitive performance of rural workers: An experimental study

The effect of tropical deforestation on heat exposure and subsequent human health outcomes remains understudied, especially among an increasingly vulnerable population - healthy, adult subsistence workers in rural industrializing tropical countries. We report on a field experiment that estimated the short-term effects of heat exposure from deforestation on cognitive performance. We randomly assigned rural, adult subsistence workers in East Kalimantan, Indonesia to deforested or forested settings, and standard or high incentive piece rate payments. Participants worked in forested or deforested settings for up to 90 min, where ambient and black globe temperatures in deforested areas were, on average, 2.1 °C and 10 °C higher. After completing the experimental task, participants were asked to take a validated general cognitive assessment test (CAT) and episodic memory test (EMT). We found participants in deforested settings had statistically significant lower scores on both CAT and EMT. Effects were largely driven by heat effects on male participants and those working after noon. Our results highlight how heat exposure from tropical deforestation may lead to declines in cognitive performance even in favorable work settings. Policymakers should consider how land use planning that takes into account the cooling services of trees can play a significant role in increasing resilience to heat from climate and land use change in the tropics.