If you live somewhere where its still warm then they are fine. You can let them in the run during the day when its warm and the sun is shining. They will come back in the house if they get too cold or not go outside at all if its too cold, just make sure they are able to find their way back in the house. Sometimes they choose to stay in the run huddled up instead of going inside, in this case they are more likely to trample and kill one while trying to stay warm. So just make a good judgement, also you might wanna wait til they are fully feathered before trying since its beginning to get cold.My chicks are 4 weeks old and have been kept in a heated hen house. At what age can they be allowed to come and go into the chicken run.