Phase 6 of Lok Sabha Elections recorded the highest heat stress

The total number of heat stress hours across all parliamentary constituencies during the 2024 Lok Sabha elections was 1,578 hours, RLS found. To understand the severity, consider this: if a city experiences eight hours of dangerous heat stress each day, it would take nearly 197 days (1,578 divided by eight) to accumulate 1,578 hours.

Heat stress occurs when the body's ability to regulate its internal temperature is overwhelmed, a situation exacerbated by high temperatures and humidity. Successive heatwaves in 2024 across swathes of India have killed more than 100 people and led to over 40,000 suspected cases of heat stroke in the past three and a half months, according to data from the Union health ministry, as reported by the Associated Press. Between March 1 and June 18, 110 people in India died after suffering heat strokes, with the highest number of deaths — 36 — reported in Uttar Pradesh, followed by other northern states including Rajasthan, Bihar, and Odisha.

The Election Commission of India (ECI) had issued advisories in anticipation of severe weather conditions after the IMD warned about the possibility of extreme temperatures at polling stations. The advisories, based on guidelines from the National Disaster Management Authority (NDMA), included avoiding outdoor activities during peak heat hours, staying hydrated, wearing appropriate clothing, and using protective gear such as hats and umbrellas.

Polling stations were instructed to store adequate drinking water, shaded waiting areas, medical facilities, and proper signage to guide voters​. Despite these measures, the heat impact was high.

“The data from Phase 6 clearly indicates an unprecedented level of heat stress. 55 out of 57 or 96.4% parliamentary constituencies in Phase 6 observed heat stress hours during the polling window, which not only affected voter turnout but also posed severe health risks to both voters and election staff,” said Ronak Sutaria, founder and CEO, RLS.

Analysis of the heat stress data reveals a troubling pattern. Phase 1, which took place on April 19, recorded 206 heat stress hours across 102 parliamentary constituencies, affecting 33.3% of them. By Phase 6, the heat stress hours had escalated to 477 heat stress hours. “Constituencies such as Sheohar in Bihar and Sultanpur in Uttar Pradesh were among the hardest hit, recording multiple hours of both humid and dry heat stress​,” the analysis said.

The state-wise total heat stress hours during elections 2024 revealed disparities in how different regions were impacted by extreme heat. Uttar Pradesh bore the brunt, recording a staggering 354 heat stress hours, followed by Bihar with 176 hours. Other states such as Andhra Pradesh and Gujarat experienced 96 and 99 heat stress hours respectively.

In contrast, northeastern states including Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, and Nagaland, along with Himachal Pradesh and Uttarakhand, experienced no heat stress hours. However, Kerala and Tamil Nadu faced considerable heat, recording 54 and 187 hours respectively. Reflecting severe conditions in the national capital, Delhi recorded 55 heat stress hours.

“Heat stroke occurs when the body’s temperature regulation fails due to prolonged exposure to high temperatures, leading to a dangerous rise in core body temperature,” said Ramesh Gupta, a New Delhi-based emergency medicine specialist. “When the body overheats, it can cause severe dehydration, organ damage, and eventually death if not treated promptly. The initial symptoms include high body temperature, confusion, headache, and nausea. Without immediate medical intervention, it can progress to loss of consciousness, multiple organ failure, and ultimately, fatal outcomes.”

Among immediate measures, an official from the ECI said the distribution of oral rehydration solutions (ORS) and first aid kits was carried out across all polling stations to counter the immediate impacts of heat stress. However, the experience of Phase 6 highlights the need for more robust infrastructure and preparedness.

Voters in Bihar and Uttar Pradesh faced extreme conditions, with many areas reporting Heat Index values above the danger threshold. For instance, Arrah in Bihar recorded a mean Heat Index of 47.46 degrees Celsius on polling day​​​. The heat index threshold value for dangerous heat stress is 41 degrees Celsius. Other states also faced significant heat stress during the elections. West Bengal, for instance, recorded 181 heat stress hours during Phase 7, affecting nearly 72% of its constituencies.

What needs to be done

The escalating heat stress from Phase 1 through Phase 7 underscores the need for sustained and systemic interventions to address the impacts of extreme weather on electoral processes​​. “The rising frequency and intensity of heatwaves due to climate change are making it imperative to rethink how we conduct elections,” Sutaria said, adding, “We need to consider rescheduling voting times, increasing the number of polling stations to reduce waiting periods, and leveraging technology to provide real-time heat stress updates to voters and staff.”

To mitigate heat stress, cities need to adopt immediate, medium-term, and long-term solutions, said experts. “Cities should think about tackling heat across different timescales,” said Pritika Hingorani, India CEO of Artha Global, a policy organisation with a focus on cities. “Given the number of people who work outdoors, cities have to step in with emergency measures in the short term. This can include heat alerts to suspend avoidable activity or cooling stations, ORS, and access to water.”

In the medium term, cities must develop heat action plans, she added. “These will typically include increasing parks and green cover, cool roofs (especially for lower-income settlements), and pavements, and an early warning system that educates residents on how to protect themselves. In the long run, cities can borrow from older planning guidelines—whether in the Old City of Jaipur or the Fort area in Mumbai, where a recessed ground floor provides for covered pavements," said Hingorani.

The unprecedented heat proves the urgent need for more adequate heat management strategies and climate-resilient planning for future elections. Enhanced voter education on coping with heat stress, improved infrastructure at polling stations, and comprehensive policy interventions are essential to ensure that elections are resilient to the growing threat of climate change.

“Unfortunately, in India, climate planning and mitigation measures to inform public events are largely ignored. Year after year, people succumb to extreme heat. It is high time we start to consider weather as one of the top priorities to influence decision-making,” said Athreya Shetty, an independent weather expert.