Authorities in Pakistan on May 21 urged people to stay indoors as the country is hit by an extreme heat wave that threatens to bring dangerously high temperatures and yet another round of glacial-driven floods. Pakistan’s most populous province, Punjab, is shutting all schools for a week because of the heat, affecting an estimated 18 million students. Zaheer Ahmed Babar, a senior official at the Pakistan Meteorological Department, said temperatures could reach up to 6 degrees Celsius above the monthly average. This week, the temperature could rise above 40 degrees Celsius in many parts of the country, Babar said.