‘Discomfort May Increase’: Asia’s Heat Wave Scorches Hundreds of Millions

Hundreds of millions of people in South and Southeast Asia were suffering on Monday from a punishing heat wave that has forced schools to close, disrupted agriculture, and raised the risk of heat strokes and other health complications.

The weather across the region in April is generally hot, and comes before Asia’s annual summer monsoon, which dumps rain on parched soil. But this April’s temperatures have so far been unusually high.

In Bangladesh, where schools and universities are closed this week, temperatures in some areas have soared above 107 degrees Fahrenheit, or 42 degrees Celsius. Those numbers don’t quite capture how extreme humidity makes the heat feel even worse.

“Due to increasing moisture incursion, the discomfort may increase” over the next 72 hours, the Bangladesh Meteorological Department said in a notice on Monday. In Dhaka, the capital, the humidity was 73 percent, and many areas in the country have experienced daily power outages.

The heat wave could lead to more cases of certain diseases, including cholera and diarrhea, said Be-Nazir Ahmed, a public health expert in Bangladesh and a former director of the national Directorate General of Health Services.

Mr. Ahmed said that people should ideally try to work earlier in the morning and later at night, when temperatures are lower. But that is easier said than done in a country where many people work outdoors.