Overview

• A study by Johannes Gutenberg University in Mainz finds that sleeping with an open window exposes individuals to nighttime traffic noise that increases stress hormones, cholesterol levels and blood pressure.
• Evolutionary alarm readiness causes the body to react to nocturnal sounds even without full awakening, leading to shallower sleep patterns and shortened recovery phases.
• The World Health Organization classifies nighttime noise as a significant public health hazard linked to long-term risks of hypertension, heart attacks and strokes.
• Experts advocate for thorough ventilation before bedtime, alongside air purifiers, soundproof windows or earplugs to maintain air quality while minimizing noise intrusion.
• Health authorities also recommend keeping doors closed during sleep to further limit external noise and safeguard sleep integrity.