How long do baby chicks need a heat lamp?

[Double T]

My guys are fast approaching 4 weeks old (on Wed). They've been in their own little pen in the chicken coop since a week and an a half when they outgrew their brooder, I've got 29 of them and have been leaving the red heat light on them at night. Our temps have been 80's to 100's during the day, and usually 60's or occasionally upper 50's at night. They have very little baby chick fuzz left, and I was wondering when I can put the lamp up??

 

[cpegram]

when they are feathered in at 4weeks you don't need it anymore...

 

[BWKatz]

Ditto...get rid of it. They'll snuggle if it gets chilly.