Rising night-time heat an urgent health hazard, Pg17

Key Highlights:

• Night-time temperatures in India are rising faster than daytime temperatures, posing a significant health risk, especially for low-income populations.
• A study in Chennai showed occupants in low-income houses frequently experience temperatures exceeding 32° Celsius at night, sometimes reaching 35° Celsius.
• Rising night-time temperatures, exacerbated by the urban heat island effect, prevent the human body from recovering from daytime heat.
• Increased night-time temperatures correlate with a rise in all-cause mortality, as seen in Ahmedabad, where deaths increased significantly when night temperatures exceeded 28-30° Celsius.

Detailed Insights:

Urban Heat Island Effect.png

• India's average temperature increased by about 0.7° Celsius between 1901 and 2018, with projections indicating night-time temperatures could rise by as much as 5.5° Celsius by the end of this century.
• The urban heat island effect, caused by concrete, roads, and lack of vegetation, amplifies night-time temperatures in urban areas by 4-6° Celsius or more compared to outskirts.
• High night-time temperatures lead to sleep discomfort, exhaustion, and reduced productivity, with potential major adverse health impacts still being assessed.
• Heat action plans in over 200 cities across at least 23 states primarily focus on heatwave situations, while the constant threat of rising night-time temperatures requires more attention.
• Passive cooling solutions like reflective roof coatings, whitewashed surfaces, and improved natural ventilation can provide immediate relief in cramped households.

Key Concepts Involved:

• Urban Heat Island Effect: The phenomenon where urban areas experience higher temperatures than surrounding rural areas due to human activities and infrastructure.
• Passive Cooling: Techniques that use natural processes to cool buildings, reducing the need for energy-intensive air conditioning.
• Heat Action Plan: A set of strategies and measures implemented to reduce the health impacts of extreme heat events.