Torrid summers, when the mercury soars 4°C to 6°C above the average and produces heatwaves in several States between April and June, may become more frequent in coming years. Not only will there be more hot days, the spells of heat stress sweeping across much of India are likely to grow longer. The scientific consensus is that heatwaves will grow stronger and expand their geographical spread in the south, influenced by the sea surface temperature in the Indian and Pacific Oceans. With rising greenhouse gases, their impact can only intensify. Though the number of people dying due to heat stress last year was half of the previous year’s toll of 2,040, the need to evolve detailed action plans at the level of States, districts and cities is now critical. It is encouraging that the National Disaster Management Authority is guiding States, in partnership with the India Meteorological Department, to evolve heat action plan protocols. The response to distress caused by excessive heat has to be both speedy and professional. Europe upgraded its preparedness to handle a crisis after a crippling heatwave in 2003 killed thousands of people, over 14,800 of them in France alone. In the Indian context, crop failures and disruption of electricity supply due to sudden peak demand are common. People experience dehydration, heat cramps and deadly heatstroke. The elderly are particularly at risk, since higher temperatures affect blood viscosity and raise the risk of thrombosis.
Better meteorological forecasting can provide an early warning about a coming hot spell during the summer window. This gives the NDMA and the States sufficient opportunity to launch an action protocol: to inform the public as soon as the temperature crosses the threshold fixed by the IMD, advise on precautionary measures, and aid those who are most vulnerable, such as older adults, farm workers and those pursuing outdoor vocations. Ahmedabad, for instance, drew up a city-level action plan in the wake of its 46.8°C heatwave of 2010 with support from public health institutions. Preparing the health system to identify symptoms of heat stress and providing treatment through urban health centres is one intervention it decided upon. Reviewing school timetables, rescheduling work timings to cooler hours, making water widely available and reserving religious sites and libraries as cooling centres were others. European and American policy responses, such as creating green and blue urban spaces to provide tree shade and higher moisture, as well as housing design that cuts heat through the albedo effect of reflected solar energy, hold universal appeal. Some of these passive defences are actually integral to vernacular practices and will serve everyone well. It is essential to study the efficacy of heat action plans and share the results across States to achieve best practices.
