Originally Posted by
jc94
Yes but it would save a few cents.
I thought pre-787 aircraft used bleed air (effectively waste heat) from the engines and cooled it, rather than heating the extremely cold outside air?
Anyway, a common problem for crew in maintaining comfortable cabin temperatures is that as OP noted, some people can comfortably wear a down jacket at 22 C while others will be sweating in a T-shirt. To observe this effect you need only travel to Southeast Asia during a "cold snap" of 20 C weather and see what kind of attire people are wearing.