Having used a Snugglesafe for various sick things in the past....hedgehogs, cats, rabbits....they are great but they do not hold the heat for that long so I guess it depends how long you intend the babies to be outside and how closely you will monitor the heat of the Snugglesafe. They can get incredibly hot to begin with, but covered with a towel, it should be fine, but they lose heat over the space of an hour or so, much quicker in lower temperatures. They also don't really radiate the heat, the chicks would need to be in physical contact with the Snugglesafe (wrapped in a towel) so if you rig an 'over head' solution, make sure it is low enough for them to actually touch it and keep a very close eye on how your chicks are behaving, to see if they are warm enough xxx