👆
As stated not predator proof, and too young for any type of unsupervised free ranging. Shorter supervised trips at those temps would be ok but they will still need to frequent heat source to warm up. Sorry to say it but even your neighbor's cat would love to see them roaming the yard and also...
At those temps and as long as they are out of wind/drafts kept dry. And have an age/feather appropriate warm spot large enough for all to warm/sleep under with your brooder lamp, they should be fine temperature wise.