How long should a 21AH cool down after charging in Summer?

The ambient temperature in my house is 40 degrees and this e-scooter had finished charging and was unplugged 2 hours ago. Some say 15-20 minutes while others say it depends on how big the battery pack is and should be given at least 4 hours to cool down.

EDIT: How long should a 21AH battery pack cool down after charging in Summer.