At first, I thought it was just something with US Airways but on my last five flights it got uncomfortably hot in the middle of the flight. Has anyone else been experiencing this?

All the flights I have experienced this have been US domestic flights. Right around mid-trip, the cabin temps have risen to a point where people (myself included) have complained.

I have experienced this on USAirways, Southwest, and Continental. The continental flight attendant said they air conditioner was cranked as far as it would go.

Before this summer, I don't recall this happening on any of my flights (I fly over 100,000 miles per year consistently).

The conspiracy side of me makes me think this is some trick the airlines are trying to conserve fuel.

Let me know if you are feeling the heat too.

Jack

first off, welcome to flyertalk ^ (your life as you know it is now over )

as to cabin temps.......imho, it's a little trick to keep the cabin temps warm so that the pax become sleepy.

http://www.boeing.com/commercial/cabinair/facts.html

I personally like a warmer plane. I hate having to carry a sweater during the summer just so I don't freeze on the plane. If i'm getting on in FLL and off in CLT, why should the cabin temp drop below 73?

I rarely find the cabin temp to be comfortable. It's either too hot or too cold, never a happy medium IMO

You do realize that at 35,000 feet or so - midflight - the outdoor temperature is freezing cold, and air conditioning is not necessary?

I'd prefer every flight being a little cool. It's much easier to bring more clothing to put on than to have everyone taking stuff off.

I've noticed that in the fall and winter planes are heated more than than in the summer, this could just be my body reacting to the temperatures but they definitely aren't all the same.

That's a good theory, but by the time the very thin air at 35,000' is compressed enough to keep the cabin pressurized it's temperature is up around 500� and definitely needs to be cooled before introduced into the cabin.

The air conditioning is not the "freon" based vapor-cycle process that we have in our homes and cars. It's an air-cycle process which compresses the air, sends it through a heat exchanger then lets the air expand back to it's pre-compression pressure. This process is repeated at least a second time. The heat exchanger is cooled by channeled outside air.

Many new planes like most 777s and Airbus A340-500s do not have personal air vents, so you cannot control your personal body temperature. So if you get warm you have to take off your shirt, and possibly your pants so you may end up in your underwear to avoid passing out if you personally get too warm. I actually recently purchased a battery operated fan to avoid the pants removal. I few years back on a trans-Atlantic flight on a 777 with no personal air vents, I became so warm I requested the crew to land the plane or decrease cabin temperature becasue in the cramped seat I was ready to pass out. They decreased the cabin temperature which made other passengers too cold. If the plane has personal air vents, no matter how warm the plane gets, I can always manage to maintain a healthy personal body temperature by directing the vent towards me. Those passengers who like a wamer plane are also comfortable.

For those passengers who become too warm on a plane, it is a health issue.

Agree entirely. This is one of those situations where there is a clear logical reason for favoring one human preference over the other. People who feel habitually cold can always put on extra clothing or blankets. Those who feel habitually hot do not have the equal and opposite freedom. I've never used a blanket on an aircraft in my life. Even with a short-sleeved shirt I still often feel uncomfortably hot in the cabin, and I resent the disappearance of the personal vents (though I have noticed them reappear in some newer aircraft that I've flown).

Ask the Korean Air board, I'm sure they have a lot of experience dealing with warm airplanes

I have noticed that planes ordered by US airlines generally have the air vents. I have noticed that many aircraft owned by non US carriers do not have the vents. It may not be that the "new planes" do not have the vents, but that the airlines did not order them.

PS - I like it cool.

I prefer it cool, and usually can do just fine by adjusting the air vents. Earlier this year I was on a NW Airlink flight which started off with a cold cabin, by midway through the flight the a/c was set so all of the vents, including the personal ones were blowing extremely hot air. With everyone complaining, the FA would only say that she had no control over the temperature. It is hard to get a happy medium for a plane load of people, but I think most flight deck crews avoid the "extremes" of too hot/too cold.

...um...am I missing something here? The OP reports cabins being too WARM, theorizes it might be the result of cost-saving measures.
IIUC, keeping the cabin cooler costs LESS than keeping it warmer, no? Or is there so little difference that cost is not really a factor (though I had originally understood it was.)
In any case, I've learned to drag my fleece b'anky AND a full-size bed pillow with me, even in Biz and First where I spend as much time as possible.

The inflight cabin temperature has no bearing on fuel economy, since the same amount of air will be bled off of the respective engine compressor stages regardless of temperature modulation.

When the FA calls and tells us it's too warm or too cold, we change the temperature. The problem is that while one passenger is complaining that it's too cold, there's another one who's complaining it's too hot. This is axiomatic in the world of aviation.