Ambient and Bedroom Heat in Relation to Sleep Health in a Marginalized Community That Is One of the Hottest in Los Angeles

The majority of Americans do not regularly get the recommended amount of sleep and sleep deficiencies disproportionately burden marginalized communities. We conducted a longitudinal cohort study measuring bedroom air temperature and humidity over three non-consecutive weeks (N = 19 participants; 409 observation nights) using HOBO loggers and sleep health using wrist-actigraphy and sleep diaries. Outdoor temperature and humidity were obtained from a nearby weather station. Linear mixed-effects regression models assessed relationships between temperature and sleep health metrics. Nighttime indoor apparent temperature ranged from 26 to 35 °C and averaged 5 °C higher than outdoors. On average, participants slept 6.7 h per night with 83% sleep efficiency. After adjustment, a 5 °C increase in indoor nighttime dry bulb temperature was associated with a 23 min reduction in mean total sleep time (β = −23.30 [−43.30, −3.45]) and mean onset latency increase of approximately 2 min (β = 1.85 [0.50, 6.65]). Nighttime heat waves were associated with a 4% reduction in mean sleep efficiency (β = −3.71 [−6.83, −0.66]) and an 11 min increase in onset latency (β = 11.32 [2.60, 20.75]). We found evidence that rising summertime temperatures reduced sleep health in a disproportionately impacted community, suggesting that climate change will worsen existing sleep health disparities.