How are they acting at 79* I have used both a heat plate and heat lamp and haven't had my heat lamp get over 85-87 and they were fine with that I use a 150 watt red lamp . I have used 250 watts also. Main thing is they are out of drafts and can't get wet.
What size bulb are you using?
What are you using for a brooder? can we see a picture?
What size bulb are you using?
What are you using for a brooder? can we see a picture?