Heat health risks need to be understood as a slow, protracted disaster

Instituting any surveillance system such as the National Heat-Related Illness and Death Surveillance is a complex task and we now have about a decade’s experience and learning. The NCDC’s evaluation, the 2024 report titled “Heat-Health Preparedness & Response Activities, National Programme on Climate Change & Human Health”, provides rich insights. The surveillance system collects aggregate data on heatstroke cases and deaths, emergency department attendance, cardiovascular and total deaths from all states and union territories from primary health centres and above. There were 48,156 Suspected Heatstroke Cases (SHC), 269 Suspected Heatstroke Deaths (SHD) and 161 Confirmed Heatstroke Deaths (CHD) in 2024 with reported increases in key daily indicators – emergency visits, total and cardiovascular deaths in the facilities.

There has been a significant increase in reported SHCs over the last couple of years: 4,481 in 2022 and 19,402 in 2023 – the mark of a maturing surveillance system. Emergency attendance in the Reporting Units (RUs) increased from 3.6 million in 2022 to 30 million in 2024; total deaths in the facility from 86 to 74,216 and confirmed cardiovascular deaths (linked to HRIs to some extent) from 47 to 2,173.

Accurate reporting is the key

What is the robustness of HRI reporting? Reporting by the constituent units exhibit an expected seasonality: 20 per cent in March to 40 per cent in July; and the peak between May 15 and June 10 comprising nearly two-thirds (62 per cent) of the annual cases correlated both with peak heatwave days and dips during the holidays and weekends. In terms of consistency of daily reporting, Gujarat, Telangana and Odisha are the better performers. The NHRIDS had 47,477 Reporting Units (RU) in 2024 and 55 per cent reported HRIs. The top three states were also Gujarat, Odisha, Telangana with 91 per cent, 89 per cent and 72 per cent of the RUs reporting respectively. Contrast this with 23 per cent of the 40,390 RUs reporting in 2023. RUs in key north and central Indian states that experience high heat demonstrated improvements in reporting between 2023 and 2024 but continue to lag behind the top three performers. There was hardly any reporting from Uttar Pradesh and Rajasthan in 2023 but nearly 50 per cent of the RUs reported in 2024. And 30 per cent or less of the RUs in Bihar, Jharkhand, Chhattisgarh, Madhya Pradesh, and Haryana reported during 2024.

Health systems preparedness is critical to providing treatment and reducing morbidity and mortality. These include availability of basic utilities, ORS (oral rehydration solution) corners, diagnostic equipment, emergency cooling equipment/appliances at health facilities, capacity building of healthcare staff as well as ambulance services. The NCDC evaluated 5,720 facilities across the country, 87 per cent of these at the primary care level. While there was relatively high reporting of availability of basic utilities, training, and community outreach, some of the more specific and critical elements need a big boost.

Emergency cooling preparedness was available in only 32 per cent of health facilities including in only 26 per cent of the primary health centres (PHCs). Diagnostic equipment was available in 53 per cent of the assessed facilities. Six per cent facilities were found to have “optimal”, 32 per cent were “adequate”, 11 per cent were “basic” and 51 per cent were “inadequate” in level-appropriate preparedness. Health facilities in Odisha were found to have the highest level of preparedness while those in Andhra Pradesh, Telangana, Haryana, and Punjab were some of the least prepared.

Preparedness levels of ambulances and mobile units are a cause for worry: Only 48 per cent had ice packs, 39 per cent had rectal thermometers (for measuring core body temperature, a marker of heat stroke), 13 per cent could provide conductive cooling (for rapidly reducing core temperature in exertional heat stroke), 63 per cent could provide evaporative/combined cooling (relatively less effective) and 57 per cent had paramedics trained in emergency management of severe HRIs.

Notwithstanding the NHRDIS, multiple government agencies report varyingly different numbers with respect to heatstroke deaths during 2000-2020: 20,615 according to the National Crime Records Bureau (NCRB); 17,767 according to the National Disaster Management Authority (NDMA) and 10,545 according to the India Meteorological Department (IMD). Independent researchers forecast up to over 1.5 million deaths annually in a high-emissions scenario or a 14.7 per cent increase in daily mortality with temperatures above 97th percentile for two consecutive days. There is a need to look beyond acute disaster framing and Heat Action Plans (HAPs) need to build in more markers such as high night temperatures, heat index or the excess heat factor; as well as making it more local and agile, beyond standard templates.

Heat stress is the leading cause of weather-related deaths and can exacerbate underlying morbidities, triggering episodic demands for healthcare. Heat health risks therefore, need to be understood as a slow, protracted disaster. Health programmes are built brick by brick; learning as we go along. At the same time, the climate emergency makes heat-health responses a moving target.

The writer is chairperson, Centre of Social Medicine & Community Health, JNU, a collaborator in the Wellcome Trust supported “Economic and Health Impact Assessment of Heat Adaptation Action: Case studies from India”. Views are personal