Nighttime temperature for BABY Brazilian Rainbow Boa

I read that is bad for brazilian rainbow boas to drop to much nighttime temperature . So how much should i drop temperature at night for BABY brb ?

I don't know about Rainbows but why drop temps at all?

I don't have a baby BRB, but I have a sub-adult and I don't drop temperatures at all. She is doing fine with having a constant temperature all the time.

Thank you for answers ! :) So without droping temperature at night .