The district records 40.8 degrees Celsius, the highest this seasons
A truck from Naogaon to Dhaka collided head-on with another truck on the western connection road near the bridge, said Bangabandhu Bridge West Police ASI Raju Ahmed.
An unidentified man was killed on the spot while another, Nazrul Islam, who was driving one of the trucks, died at the state-run hospital in Sirajganj town. Two others are being treated at the hospital.
In a separate incident, a woman, Shahara Khatun, succumbed to her injuries on Thursday, said resident physician of the hospital Faisal Ahmed.
She was brought in late Wednesday with injuries sustained from an accident involving a motorcycle.