·       Heatwave is declared when temperatures cross 40°C in plains, 37°C in coastal areas, and 30°C in hills, with specific criteria for departure from normal temperature ranging from 4.5°C to 6.4°C, and actual maximum temperature criteria ranging from ≥ 45°C for heatwave and ≥47°C for severe heatwave.

·       Favourable conditions for heatwaves: Transportation of hot dry air, absence of moisture in the upper atmosphere, cloudless skies, and large amplitude anti-cyclonic flow over the area.

·       Impacts of heatwaves: Health hazards such as heat stroke, increased strain on water and energy sources, and food insecurity due to crop wilting, stunting, or early ripening.

Key initiatives

·       IMD issues color-coded impact-based heat warnings jointly with the National Disaster Management Authority (NDMA), including Green (No action), Yellow (Be updated), Orange (Be prepared), and Red (Take Action) alerts.

·       NDMA’s guidelines include the preparation of action plans for the prevention and management of heatwaves, and states prepare Heat Wave Action Plans accordingly.

·       The National Action Plan on Heat Related Illnesses aims at effective preparedness of health facilities to address heat impacts and manage cases.