Cold stress during winter over North India: Patterns, trends, and mortality risks

Area of Science:

• Biometeorology
• Climatology
• Public Health

Background:

• Winter cold temperatures in North India cause significant discomfort and cold stress.
• Understanding cold stress trends is crucial for public health and safety during winter months.

Purpose of the Study:

• To investigate cold stress conditions and their trends in North India from 1982-2020.
• To analyze the impact of cold stress and wind chill on cold wave-related mortality.

Main Methods:

• Utilized the Universal Thermal Climate Index (UTCI) to assess cold stress.
• Analyzed meteorological data for North India during November-February (1982-2020).
• Examined trends in slight and moderate cold stress categories and their correlation with mortality data.

Main Results:

• A significant increase in slight cold stress hours (UTCI 0°C to -9°C) was observed, particularly in high-altitude regions.
• Moderate cold stress hours (UTCI -9°C to -13°C) showed a decreasing trend in plains states like Rajasthan, Punjab, Haryana, and Uttar Pradesh.
• Cold stress, amplified by wind chill, remains a significant factor in cold wave mortality, with Uttar Pradesh, Punjab, and Bihar recording the highest deaths.

Conclusions:

• The study indicates a shift towards less severe cold stress conditions in North India.
• Despite the trend towards milder stress, the combined effect of cold and wind chill poses a substantial mortality risk.
• Targeted public health interventions are necessary to mitigate cold wave-related deaths.