New research indicates that bedroom temperature significantly impacts heart health, particularly for older adults. Lead study author Dr. Fergus O'Connor of Griffith University explains that heat forces the cardiovascular system to work harder to circulate blood for cooling, creating stress and limiting recovery.

Man sleeping peacefully in bed, resting on his side under a gray blanket in a softly lit bedroom

A "free-living" study monitored 47 participants averaging 72 years old during an Australian summer. High-tech fitness trackers monitored heart rates overnight, while sensors recorded bedroom temperatures.

Older woman sleeping in bed

Results showed that at temperatures between 75 and 79 degrees Fahrenheit, the risk of a clinically relevant drop in heart recovery increased by 40%. This risk doubled between 79 and 82 degrees Fahrenheit, and nearly tripled above 82 degrees Fahrenheit. For individuals aged 65 and over, maintaining overnight temperatures around 75.2 F (24 C) reduced heightened stress responses during sleep.

Man half-asleep in his bed, shot from the ceiling

Researchers acknowledge the study's observational nature and limitations, including its focus on older Australian adults and the use of wearable devices. They highlight a critical gap in public health guidance: a lack of recommendations for optimal nighttime indoor temperatures.