I put my four chicks outside yesterday for their first night out of the brooder, too. A Buff Brahma (Charlotte), a bantam Black Cochin (Lola), and two Silver Sebrights (Alice and Georgia, names which can be changed to masculine versions fairly simply: Alex, George).
I peeked in on them after dark, and they were making depressions in the pine shavings, stretching out under the heat lamp. Yah, I know I'm a softy, but they've had heat-lamp "slop-over" from the second brooder in the bathroom holding younger chicks, so I wanted to avoid temperature shock. I might or might not turn the lamp on again tonight....
But they survived just fine and are dashing about in their smallish pen inside the big run where the other chickens can see them, and they can see the Big Chickens. Charlotte just tried to chest bump Betsy through the poultry fence.
Betsy, Ellen, Rhoda, Laverne & Shirley are the "older teenagers" now integrated with the Big Chickens. They're about 15-16 weeks old. They hang out in a gang by themselves, mostly, unless it's treat time.
Matilda and Bernadette are ticked off about the poultry fencing pen around the Duck House, which is the lodge where the aforementioned four are spending their segregation/integration time. They used to sneak into the Duck House to lay their eggs.
Now and then one of the Sebrights gets separated from the other, just around a corner of the Duck House out of sight, and it peeps like the dickens. I've had to gently herd the other three back into sight.
And just think, I get to do this yet again this year with the other four chicks still in the brooder. "The First Night Outside" does NOT get any less worrisome, just because I've experienced it with previous chicks!