B737 flight attendant experiences possible hypoxic signs during cruise.

Narrative:

On taxi; immediately prior to takeoff; I experienced tingling sensations in my hands. This tingling continued and at cruise altitude of FL390 my feet began tingling as well. Having previously experienced a slow decompression on a B737 and being aware that these sensations indicated I was going into a hypoxic state; I became quite alarmed. I asked my flying partner if she was experiencing these symptoms and she replied negatively. She was also quite a bit heavier than I am. I called the cockpit immediately and requested an increase in air flow. I also asked the first officer if they manipulated the air flow to increase fuel consumption. He replied that they did not. Within 1 min my hypoxic symptoms were gone. I called the cockpit to let them know this and the captain asked me to come up when they needed a break. I did this and the first officer left the cockpit. Captain then informed me that on 'long hauls' he did manipulate the outside air flow to increase fuel efficiency. At this point I realized that air quality (and my brain cells) was being compromised in the pursuit of fuel efficiency. I believe this situation is an alarming one and that all flight crews should be aware of the symptoms of hypoxia and the consequences of manipulating air flow to the detriment of air quality.

Original NASA ASRS Text

Title: B737 FLT ATTENDANT EXPERIENCES POSSIBLE HYPOXIC SIGNS DURING CRUISE.

Narrative: ON TAXI; IMMEDIATELY PRIOR TO TKOF; I EXPERIENCED TINGLING SENSATIONS IN MY HANDS. THIS TINGLING CONTINUED AND AT CRUISE ALT OF FL390 MY FEET BEGAN TINGLING AS WELL. HAVING PREVIOUSLY EXPERIENCED A SLOW DECOMPRESSION ON A B737 AND BEING AWARE THAT THESE SENSATIONS INDICATED I WAS GOING INTO A HYPOXIC STATE; I BECAME QUITE ALARMED. I ASKED MY FLYING PARTNER IF SHE WAS EXPERIENCING THESE SYMPTOMS AND SHE REPLIED NEGATIVELY. SHE WAS ALSO QUITE A BIT HEAVIER THAN I AM. I CALLED THE COCKPIT IMMEDIATELY AND REQUESTED AN INCREASE IN AIR FLOW. I ALSO ASKED THE FO IF THEY MANIPULATED THE AIR FLOW TO INCREASE FUEL CONSUMPTION. HE REPLIED THAT THEY DID NOT. WITHIN 1 MIN MY HYPOXIC SYMPTOMS WERE GONE. I CALLED THE COCKPIT TO LET THEM KNOW THIS AND THE CAPT ASKED ME TO COME UP WHEN THEY NEEDED A BREAK. I DID THIS AND THE FO LEFT THE COCKPIT. CAPT THEN INFORMED ME THAT ON 'LONG HAULS' HE DID MANIPULATE THE OUTSIDE AIR FLOW TO INCREASE FUEL EFFICIENCY. AT THIS POINT I REALIZED THAT AIR QUALITY (AND MY BRAIN CELLS) WAS BEING COMPROMISED IN THE PURSUIT OF FUEL EFFICIENCY. I BELIEVE THIS SITUATION IS AN ALARMING ONE AND THAT ALL FLT CREWS SHOULD BE AWARE OF THE SYMPTOMS OF HYPOXIA AND THE CONSEQUENCES OF MANIPULATING AIR FLOW TO THE DETRIMENT OF AIR QUALITY.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	691148
Time
Date	200602
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Altitude	msl single value : 39000
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight attendant : on duty
ASRS Report	691148
Events
Anomaly	cabin event other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Cabin Crew Human Performance Flight Crew Human Performance Aircraft
Primary Problem	Cabin Crew Human Performance