kaka

However, as a health conscious person of Chinese decent, I grew up knowing i should drink warm water but i still have insanely low tolerence for hot weather - I'd just sweat like a pig if it's warm (like 25C!, and no, i'm by no means over-weight.)

I still find JL flights warm in general. Too warm every time I fly and then wake up in sweat. This is of course worse when I dont get 2 seats to myself (so i can move around)

JALPak

But the point was majority of the passengers felt it's cold enough to use the blanket/cardigan under the current temperature setting. I am sure lowering the cabin temperature would make you more comfortable, I am just not so sure about if that would be the case for the majority of the passengers on JAL flights.

R&R

In case you missed this:
The problem of hot cabins and the sensation of coldness has been discussed at length in the past. Any temperature over 78 degrees and the DRY air decreases the exchange of Blood levels of Oxygen & Carbon Dioxide in the lowered pressure cabins resulting in shortness of breath, headache, anxious feelings, etc.

Of course, they should use the blankets, sweatshirts, sweaters, if they
feel cold! But the cabin temperature should not be raised for everyone to compromise their health! It appears that eludes your understanding.

JALPak

Seems like we were talking about 2 different things. I was referring to cabin temperature on JAL flights while you kept talking about 78F. Although I don't travel with a thermometer, I have never experienced anything close to 78F up in the air on JAL metal.

I've spent ~800 hours on JAL flights in the past 10 years, the only time I experienced something close to 78F inside a JAL plane was when it was parked at NRT waiting for departure. But that's the summer after the Tohoku earthquake and I don't mind as it had to conserve energy for the area.

KPT

JAL's target clientele (not you) is comfortable sleeping at 82F with a blanket. This is the same country where you will routinely see people dressing casually in long sleeve shirts with an additional layer underneath and long pants when it is 100F and 70+% humidity. Clearly they do not share the same health concerns you have.

If you have a problem with that, fly a different airline. JAL's domestic customers most likely expect the same experience internationally, which is a warm cabin. Nothing wrong with that.

The reverse would be true -- if someone who is Japanese and usually fly JAL complain to AA or any other airline that all their flights are too cold, and that the cabin temperature should be set to 82F -- would you expect results?

EDIT: The last time I flew JAL was back in '06, but this was after spending months in the intense, humid, and prolonged Japanese summer heat. A relatively dry 82F would have been a blessing

virmaior

R&R, you keep assuming that Japanese people (and more specifically Japanese scientists) agree with these findings. Most likely, the vast majority of Japanese people have never heard of this and would probably just disagree or claim that Japanese people are different...

I am not trying to validate their claims so much as explain that there's a cultural difference at work here, and you're assuming there's a fact of the matter that Japanese people would accept and alter their behavior for.

Unimatrix One

I flew SFO-HND last Thursday. I was sleeping nicely until I woke up sweating and couldn't fall asleep again due to the heat. I complained to a FA. First time I've done that in 10 years flying JAL.

AlwaysAisle

I am PhD chemist with biochemistry background. I am little interested to know which study indicates such physiological nature. I just little curious what research data showed such tendency.

thechosenuno

I flew JAL NRT-BKK, and it was so hot I thought I was getting delirious. The FA, though, noted how warm I was and brought me iced down towels. Let's just say it was a long, long flight.

Also had an experience at the Mandarin Oriental Tokyo where I had to ask them not to adjust the temp on the A/C upwards when they cleaned the room. They stopped, and the room stayed a comfy (for me) 72 degrees.

R&R

How do you explain the difficulty with hot cabins?
Do you have any knowledge of Human Physiology or oxygen deficit with the reduced cabin pressure and reduced oxygen at elevated altitudes in a plane or climbing a high mountain? Of course, you realize they have similar effects! These medical conditions are not studied in General Biochemistry.

Last nite, I confirmed these problems with a friend at NASA, who is trained in Aeronautical Medicine and Emergency Medicine, who cares for the astronauts and works at Mission Control for the shuttle flights. But want to assure you we did not discus or laugh at the thought of cultural differences of the various astronauts having similar problems!

If this problem is so common on JAL and other Asian airlines, it is a matter to be investigated by the FAA or other responsible agencies!

Sarfa33

I believe that R&R is trying to describe Hypoxia. As the ambient temperature increases, the volume of a gas will increase (Boyle's Law). This means that inhaling the same volume of air into your lungs will yield a lower number of o2 molecules actually making it into your bloodstream.

However, I question whether there is really some kind of line at 78 degrees, above which humans will begin to have problems. A 4 degree F (2 degree C) difference (between 78 & 82 F) seems too small to me to really have any kind of a significant effect. I tried to find anything online that referenced such a phenomenon but was unsuccessful.

-S

zznoname

Yes hot. NRT-ORD last week. Too hot. I asked FA to cool it down a bit and they did. Just a tiny, tiny bit. Way too hot. Uncomfortably hot.

R&R

I assume it was not a 'cultural' hot problem,
that would not have been possible to correct!

I am sorry I made reservations on JAL for more convenient connections on a return from China in Oct.

If there is doubt in your mind, read this post on another really hot previous string.


Quote:
Velezray,
"Unrelated to ANA, I was on a flight years ago from Karachi to BKK and the temp and the conditions made it hard to breathe. I felt like I was going to suffocate. I finally got up to advise the flight crew and walking to the galley noticed that ten or fifteen passengers were passed out. The crew had not noticed it as they were too busy gossiping. They called the cockpit (i think), the air circulation improved and the situation became normal."

http://www.flyertalk.com/forum/all-n...xperience.html

AlwaysAisle

Yes, but hypoxia is related to the altitude, not caused by temperature. People with respiratory problems may start to experience hypoxia anywhere from 5,000 ft. altitude. For people without respiratory problem hypoxia, or altitude sickness, usually comes at altitude above 10,000 ft. The commercial aircraft we fly are set to cabin atmosphere anywhere between 4,000 ft. - 6,000 ft. altitude.

Denver, CO is located at elevation of 5,280 ft. During summer time high temperature easily reaches mid 80 F. There are many people working outside, such as construction workers, farmers, etc. Do they experience shortness of breath, headache, and anxious feelings? No, they do not. Any healthy people at 6,000 ft. altitude when temperature is in mid to high 80 F typically do not experience such symptoms. There are hundreds of passengers arriving at Denver everyday who are not accustomed to high altitude condition. Do they experience hypoxia during summer time? No they do not.

Blood oxygen level and carbon dioxide level in human blood is a function of binding coefficient with hemoglobin. Hemoglobin molecular in our blood has iron molecular in the center. Oxygen and carbon dioxide binds (secondary bonding, not covalent bonding) with iron center of hemoglobin. How efficient oxygen and hemoglobin can bind determines blood oxygen level. The chemical reaction mechanism study of oxygen and carbon dioxide with iron core of hemoglobin is exactly what us physical biochemist study. Thank you for lecturing me about what biochemist is, R&R.

I appreciate Sarfa33’s comment, but chemist in me just cannot let this go. Boyle’s Law deal with constant temperature situation. Cannot describe variable temperature conditions. To deal with temperature increase we need Ideal Gas Law (PV=nRT). Sorry, I am not putting you down, Sarfa33. I do appreciate your comment.

Anyway, even FAA does not require pressurization of cabin when aircraft is flown below 10,000 ft. altitude. I often go up to 10,000 ft. altitude on Cessna 182, where this particular aircraft does not have pressed cabin, and not just me but everybody else are just fine.

There is a big, big difference between altitude sickness and crying and whining about the temperature.

Sarfa33

Actually, hypoxia really just describes a reduced amount of oxygen entering the bloodstream. Most often, this is caused by an increase in altitude, but that is not the only situation that can cause hypoxia.

Temperature, for example, does have an effect on the oxygen-hemoglobin dissociation curve. See this graph. According to the graph in the upper-left, under the same partial pressure of oxygen, the % saturation of hemoglobin with O2 will actually decrease as temperature increases. So theoretically, then, a person could suffer from hypoxia while standing outside at sea level if the temperature were hot enough. In reality, there probably isn't any place on the surface of the planet that gets hot enough for that to happen.

However, again in theory, one could see how a higher temperature could exacerbate the effects of high altitude (reduced partial pressure of O2), causing the onset of hypoxia sooner or more frequently than at lower temperature. In reality, though, as I said and as you pointed out, I'm not sure that 82 F is really warm enough to make a difference.

And with that, I'm done hijacking this thread. Feel free to PM me if you want to discuss further.

-S