I used to help with Beaver camps. I always took extra fleecey blankets and battery powered fairy lights, so anyone feeling a bit nervous could have night lights strung inbetween the tent layers, and a cuddly blanket. Leaders take shifts and patrol around the tents (or sit in the door way if it's an indoor one) so anyone who's upset but not coming forwards gets heard and checked on.
I've only once had children need to go home, one of whom was sent with one of those toddler airbeds with the built in blanket, so sleep on. Nothing else. We had to use leaders spare equipment for him, and the poor lad just couldn't settle.
The kids are usually so busy with all the things going on, and having a blast with their friends. Homesickness is rarely an issue.
There's also a lots of risk assessments and training that have to happen before you're allowed to run a night away, and the activities are usually things the leaders have done plenty of times before. When we've done extra stuff, like archery or wall climbing, we've had specialists join us to run it.
Both my girls have done several camps now and they absolutely love them. My youngest is also off to cub camp this weekend and she's very excited. We also have a facebook page to watch for updates, and have little to no direct communication for the duration. One leader usually has the single point of contact phone, and everyone's details, in case of emergency. But there's usually plenty of pictures and updates on the facebook page, and of course the epic post camp run down from my girls when they get home and have to tell us everything. 😃