PM Narendra Modi took to social media shortly before polls re-opened on Friday to urge those voting to turn out in "record numbers" despite the heat.

Millions of people in India are battling sweltering conditions to take part in the world’s biggest election as a severe heat wave hits parts of the country and authorities forecast a hotter-than-normal summer for the South Asian country.

The India Meteorological Department (IMD) said Thursday that severe heat wave conditions would affect parts of the country’s southern and eastern region through the weekend, including four states that are voting on Friday.

Parts of West Bengal, Bihar, Uttar Pradesh, and Karnataka are among 13 states and union territories voting in the second phase of the mammoth elections, with temperatures forecast to exceed 40 C (104 F) in some areas.

India’s election commission said earlier this week that it had formed a task force to review the impact of heat waves and humidity before each round of voting.

The Hindu newspaper suggested that the decision could have been taken out of concerns that the intense heat “might have resulted in a dip in voter turnout”.

Prime Minister Narendra Modi is widely expected to win a third term in the six-week election, which concludes in early June.

But turnout in the first round of voting last week dropped nearly four points to 66% from the last election in 2019, with speculation in Indian media outlets that higher-than-average temperatures were to blame.

On Thursday, Baripada in the eastern state of Odisha hit 43.6 C (110.4 F) and Telangana’s Khammam in the south reached 43.4 C (110.1 F), according to the IMD, which warned last month that India would likely see stronger and longer heat waves this year due to above-normal temperatures.

Modi took to social media shortly before polls re-opened on Friday to urge those voting to turn out in “record numbers” despite the heat. “A high voter turnout strengthens our democracy. Your vote is your voice!” he wrote on X.

The election commission said in a statement Monday that “there were no major concerns” about the impact of hot temperatures on Friday’s vote and weather forecasts indicate “normal conditions” for the constituencies voting.

The commission, however, added that it had been closely monitoring weather reports and would ensure “the comfort and well-being of voters along with polling personnel”.

It released guidelines for staying cool at polling stations, including drinking water and carrying an umbrella. It also warned against leaving children or pets in parked cars.

In eastern Bihar state, temperatures above 41 C (105 F) are forecast every day until May 1 in the Banka district, according to the IMD. Election officials have extended voting hours at some polling stations in the state “in view (of the) prevailing heat wave”.

More than 968 million people are eligible to take part in India’s election, with the final round of voting on June 1 and results expected three days later.

A wave of exceptionally hot weather has blasted South and Southeast Asia, prompting thousands of schools across the Philippines and Bangladesh to suspend in-person classes.

India, the world’s most populous nation with 1.4 billion people, often experiences heat waves during the summer months of May and June.

Last year successive heat waves hit the country, closing schools, damaging crops, and putting pressure on energy supplies. In June alone, temperatures in some parts of India soared to 47 C (116 F), killing at least 44 people and sickening hundreds with heat-related illnesses.