Jashore had the previous highest temperature of the season at 42.6C
Shihab lived with his parents in the neighbourhood of Dhalpur in Dhaka.
Citing local residents, Jatrabari Police Inspector Tofail Ahmed said Shihab engaged in an altercation over mangoes with his playmates in Dhalpur area on Wednesday.
The next day when he went to play cricket in the nearby playground, a group of 20 to 25 playmates, including Hridoy and Jewel, chased him and attacked him with sharp weapons.
Later, locals took him to hospital with critical injuries.
Police opened a case into the incident and arrested Hridoy as one of the suspects.