Research Publications

Introduction: The burden of heat- and cold-associated mortality is significant in the U.S. and globally. However, the impact of temperature on non-emergency health effects is unclear. Prior research suggests associations between extreme indoor temperatures and both cognition and sleep. These associations are potentially stronger in U.S. households facing energy poverty, i.e., living in inadequately weatherized homes and/or lacking resources to afford heating and cooling. We examined short-term associations between indoor temperatures and cognitive function and daytime sleepiness in residents of low-to-moderate income areas of Detroit, Michigan. Methods: A temperature monitor recorded hourly temperatures in the homes of 29 participants from August-October, 2019. Participants were telephoned 2-5 times and administered tests of cognitive function (forward and backward number recall, word list immediate and delayed recall after a 5- minute delay) and questions from the Epworth Sleepiness Scale. Indoor temperatures were available for 15 participants and 40 person-days of cognition and sleepiness tests. Associations were estimated using fixed effects models with nonlinear distributed hourly lags of temperature up to 24 hours prior to testing. Results: Indoor temperatures ranged from 16-35 C. Associations between temperature and sleepiness or forward number and word list recall scores were not significant. Point estimates, however, were consistent with hypothesized deleterious effects at both high and low temperatures. For backwards number recall scores (scale of 0-3 points), at the time of the test (lag 0), for 35 C vs. 25 C, we observed a -0.54 point change in score (p = 0.06), i.e., worse ability to recall, with evidence of additional effects from temperatures at earlier hours. Conclusions: Low-to-moderate income Detroit residents experience high indoor temperatures in the summer and fall, and indoor temperature may influence cognitive function. Further research on indoor temperatures and health is warranted to inform weatherization and utility assistance policies.