I live in San Antonio Tx. I got 8 pullet chicks and 2 pullet turkey from a local feed store. The temps this time of year are 70 at night and upwards of 100 during the day here. The pullets are going on three weeks old. I have not had them under any type of heat source and they all seem to be doing fine. Is there a reason to have them in a brooder or under a heat source at this stage of their life and with these temps?