A wave of exceptionally hot weather has blasted Southeast Asia this week, sending the mercury to 45 degrees Celsius (113 degrees Fahrenheit) and prompting thousands of schools to suspend in-person classes.

Even before the chaos and conflict unleashed by the military's 2021 coup, Myanmar's creaky and outdated electricity grid struggled to keep fans whirling and air conditioners humming during the hot season.

Now, infrastructure attacks and dwindling offshore gas reserves mean those who cannot afford expensive diesel generators must face at least eight hours daily at the mercy of the scorching heat.

For many in the city of some eight million, relief comes only at night and outdoors with the metropolis' parks offering natural shade and blissful breezes.

"My parents can't stay inside their house in the afternoon," one Yangon resident told AFP, as she visited Inya lake late Friday.

"They have to go outside and sit under the shade of trees."

The woman said her parents warn her about going outside in the weather, urging her to cover up, and added: "I feel this year is far hotter than last year."

Mya Aye, 62, said she comes to the park every day when the power goes off at 5:00 pm.

"The weather at home is so hot that neither the children nor the elderly can stay," she said.

Across swathes of Myanmar's arid heartland day temperatures on Thursday were 3-4 degrees Celsius higher than the April average, according to the country's weather monitor.

In Chauk in Magway region, the temperature reached a blazing 45.9 Celsius (114.6 Fahrenheit) on Wednesday, the office said.

Back at the picturesque lake, one man told AFP he and his family had travelled from the northern part of the city as they could not remain at home because of the heat.

"Even if we sit outside, the sun's rays are very hot and we can't sit anywhere," he said.

"After 10:00 am in the morning, it's getting hotter and we can't stand it," he said, adding that older people were particularly impacted.

"Elderly people are not going outside because of the heat and they just stay inside. After the sun is gone, they come out," he explained.

The frequent power outages only made the situation worse, he said, with homes emptying each evening.

"When there is a power blackout everyone sits out on the street until 9:00 or 10:00 pm," he said.

Global temperatures hit record highs last year and the UN's World Meteorological Organization said Asia was warming at a particularly rapid pace, with the impact of heatwaves in the region becoming more severe.

Scientific research has shown climate change is causing heatwaves to be longer, more frequent and more intense.