Are my Chicks ready to go outside?

[Seahawks24]

I have a mixture of chicks they are all about the same age except one. This picture is of the older chicks they are all about the same size. First do you think they are ready to go outside Lows of 40 with a heat lamp. But I have one little brown leg horn that is 3 weeks younger she will have to stay inside I am thinking. Will it be easy to put her in the coop when she is older? Thanks Mary

 

[curious chickee]

My two week olds have been outside since I first got them with a heat lamp, they have a three sided cuddle spot with shavings and a heat lamp, the heat lamp ranges from 80 during the day to 65 at night. They usually hang out on the edges of the lamp. Our highs today were 63 and low 48. They are happy little chicks exploring then warming back up under the light when needed. My older chicks lost their lamp around 3-4 weeks when they weren't really hanging out under it anymore.

.

This little coop is inside my run.

 

[tsmith91]

You can really put them out anytime as long as they have a heat source many people brood in the coop