After a slight decrease from severe levels, the mercury is hovering around 40 degrees Celsius in most regions
The accident occurred on the Dhaka-Khulna Highway around 2:30am on Sunday.
A Sugandha Paribahan bus headed from Dhaka to Barisal veered out of control and struck a culvert before crashing into the ditch, said Police Sub-Inspector Mahidul Islam.
Six died on the spot. The Bhanga Highway Police and fire service officials rescued 28 and sent them to Faridpur Medical College Hospital for treatment.
Two, including 28-year-old Dipon Biswas, died in hospital, officials said.
Bus supervisor Asim Majhi, 35, and passenger Hasan Mia, 25, were identified among those who died on the scene, SI Mahidul said.