I had 5 different Foster kids grow up with me at different parts. All were different ages and had different needs. Having safe or different people for someone to stay with for a while makes a big difference. My first Foster sister was 14 and basically looked after herself to a large degree aside from needing to be kept an eye on. 2 had learning and developmental disabilities, and while it made life a bit exciting and unexpected honestly most of the time it was just a novelty. They had quirks that their full time carers just needed a break from every 2 months or so. Probably shouldn't say this but that value you can give to someone does actually come back to you not inconsiderably money wise too, my mother was always honest about that when people said she was "a Saint I could never do it" etc. The older kids are actually where people need to step up more.

Ah right so the latent heat of fusion or freezing isn't lost because both are used to cancel each other out and deliver more energy exchange