Heat source for peachicks

[BabyPea]

I have read that when peachicks are in the brooder you start the first week 95° degrees and that each week deduct 5°. I have also read that you keep the heat until 4mo of age. I'm confused on what I should leave the hestsource.
I'm in Texas the brooder room is 90s right now but I still have the heat at night. I have a few that I have outside and in that cage I put the heat on at night. At what age can you remove the heat.
I am leaving for a night out of town and I hate leaving heat lamps on. The outside night temperature is mid 70s. Will that harm a 2.5mo peachicks?
The ones inside has a heater inside the brooder so I'm not worried about those.

 

[KsKingBee]

They will be fine without the lamp as long as they are sheltered out of the elements. Ours go outside to the open air brooder and only have heat lamp on when it gets below 65* at night. By twelve weeks they need no supplemental heat.

 

[BabyPea]

They will be fine without the lamp as long as they are sheltered out of the elements. Ours go outside to the open air brooder and only have heat lamp on when it gets below 65* at night. By twelve weeks they need no supplemental heat.

I appreciate your wisdom.