Dhaka dwellers experienced 40.7 degrees Celsius temperature Thursday which is the second highest in the last 54 years, report agencies.
The country's highest temperature was recorded in Jessore, 42.4 degrees Celsius, the hottest day this year so for.
The Met Office recorded the highest temperature in Dhaka on April 30, 1960, which was 42.3 degrees Celsius.
Severe heat wave is sweeping over Dhaka, Tangail, Faridpur, Rajshahi, Ishwardi, Khulna, Mongla, Jessore and Chuadanga regions and moderate to mild heat wave is sweeping elsewhere over the country.
For the last few weeks, the mercury has been creeping up mercilessly and there is no chance of rain in the next few days.
An official of Bangladesh Meteorological Department said the country will get no respite from the hot weather because the heatwave is likely to sweep over it for the next few days.
"We expect rainfall in the country soon. After the rainfall we will get relief from the intolerable hot weather," he added.
The Met Office sources said the country is witnessing less rainfall than usual in the month of April, which is causing extreme hot weather.
The temperatures in the city were more than 35 degrees in April. The hot weather may continue until April 27.
Meanwhile, Finance Minister AMA Muhith expressed his disappointment Thursday with the power and energy ministry's present performance. He said that he feels bad when he hears about the difficulties in the power supply.
"When we took the office, there was serious power crisis. The government took strong measures and the power production capacity has reached from 3500 megawatt (mw) to 11,000 mw", he said.
"With this, a demand of 6600 mw can easily be met. I believe, the people in Power Division and Energy Division should take a serious note. This cannot happen," he added.
It cannot be acceptable that with the increased production capacity of 11,000 mw, demand for 6600 mw of power can not be met, he said.
The extreme hot weather has led to a spurt in diarrhoea cases in the capital and the situation may remain unchanged during the next few days, doctors said.
Health experts told the news agency that diarrhoea disease has broken out in the city as temperature continued to rise.
Chief of the Short Stay Unit of the International Centre for Diarrhoeal Diseases Research, Bangladesh (ICDDR,B) Dr Azharul Islam said, "A large number of people, mostly adult, is being admitted to ICDDR,B every day and this trend may continue for the next few days."
As many as 780 patients were admitted to ICDDR,B Wednesday while 720 patients on April 22, he said, adding diarrhoea cases slightly increased Thursday. As many as 365 patients were admitted to the hospital till 1.0 pm Thursday and 361 patients were admitted during same time on Wednesday, Dr Azharul added.
Chances of food and water contamination are very high during this abnormal hot weather, he said adding, "We should take de-contaminated food and pure water to avoid diarrhoeal diseases."
The ICDDR,B sources said a total of 5500 patients have been admitted to ICDDR,B since April 14.
With the growing number of people attacked by diarrhoea in the capital, the doctors suggested the people to drink purified water to avoid diarrhoeal diseases.
The number of diarrhoea patients usually goes up during hot weather, they said adding that the ongoing abnormal hot weather may cause spread of different diseases including diarrhoea among people, particularly children.