Cabin temperature differences
 

Traveling transatlantic both ways recently, both times upgraded to Premium Plus with Plus Points (and yes, both times they took 40PP instead of 20, so I shall have to get them back — why does this always happen?!).

One way was on a 787. I was quite cold and used the blanket a lot.

The other way was on a 777 type 77E. I was reasonably warm (but still used the blanket) and was struck how, every time I went back to the lavatories, stepping into Economy was like an expedition to the Antarctic — a large drop in temperature between row 22 (back row of PP) and 31 (front row of Economy Plus). It made me shiver. I had never been previously aware that it was even possible to have such massively different temperatures in different but adjacent parts of the plane. I found myself wondering whether those in the back were in a colder zone in order to save the airline money, but surely it can't make that much of a difference?

Some widebodies are divided into zones, each with its own thermostat. So the temps can vary significantly within the plane depending on who controls it (sometimes pilots and FAs AFAIK).

I’d be very surprised if they dictated the temperature within the zones though and even more surprised if it were to actually save money.