I have frequently been asked by cc on night flights to turn up the temp to "make the pax sleep" to give then a quiet trip home.
I thought the research evidence was that people slept better when the temp went down a couple of degrees? Need to keep the feet warm, but that's easily done.
I understand about the difficulty of controlling the different zones, and different personal thermostats (I was brought up in England, pre-North Sea Gas, my wife in Australia), but it's possible that if FAs are asking for the temps to go up to quieten us down, they're actually going the wrong way.