Can i put runt outside with sibilings?

[wendy2012]

Hi there! So I have a slow growing runt in my flock. 2 other chicks a lot bigger. So I live in CT and at night past few days can go down the upper 30s to 40s. At the moment it is 46 degrees. Supposed to go down to 39 degrees. So that chick runt and i dont think shes fuy feathered. I put cardboard in the coop and put a thick plastic to help with coop to stay a little warmer. She lives with 2 others and they always huddle together when asleep. Should I worry about my runt in the coop with temperature? I attached a pic so you can see runt and its feathers. They are 8 weeks old including runt.

 

[NatJ]

I attached a pic so you can see runt and its feathers.

I'm not seeing the picture.