Date: 201602
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Flight Attendant (On Duty)
Reporter qualification: Flight Attendant Current
Human factors: Physiological - Other
Second reporter function: Flight Attendant (On Duty)
Anomaly: Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Flight Deck / Cabin / Aircraft Event Illness / Injury
Detector: Person Flight Crew; Person Flight Attendant
When detected: Pre-flight
Result: General Physical Injury / Incapacitation
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: Arriving at the aircraft; we (all but the Captain) were met by a member of the station; explaining the situation discovered when remoting the aircraft from its parked position to the gate. There was a fire warning light that wasn't clearing on one of the engines and the heater cart had been blowing exhaust into the cabin all night long. We boarded the aircraft and were quickly overcome by the fumes. All doors were opened in an attempt to vent the aircraft; and we discussed with Operations delaying boarding for this operation. Our customer load was light; and we were early so we anticipated being able to make the situation acceptable before departure.The Captain's initial reaction was; 'it's not that bad'; and 'the flight attendants want to delay the flight; we're going to be late.' We had plenty of time; at that point; and an agreement from the Operations Agent working and an Operations Supervisor. The Captain did have the outside air removed and started up the APU to allow the re-circle fan to start its job of clearing the cabin.Cabin air seemed to get a little better; or we got used to the environment. I suggested to the Operations Agent that she let our customers know what was going on with the smell in the cabin; in case anyone had issues that may come into play. We boarded the flight and pushed 5 minutes early. We arrived [at our destination] more than 20 minutes early!During the flight; I started to experience a headache; and asked the 'C' FA if she was having the same. She had just taken a pain reliever for hers. I later asked the 'B'; who was experiencing nausea from the lingering smell.In [several enroute stations]; fellow employees commented on the cabin atmosphere [and] both the Operations Agent working the flight and the ramp agent in the back asked about the odor.I was not feeling better and called in sick for the remainder of my pairing. My headache actually worsened; at first; in the fresh air; but did ultimately clear.I wish I felt comfortable; as a flight crew member; saying 'this aircraft is unacceptable for customer travel'. I think an honest report to Dispatch; from the station personnel; would have resulted in a swap or cancellation; until this aircraft could be cleared.


Second narrative: When arriving at the gate this morning; we were told by an Operations Supervisor that the heating cart used overnight had allowed fumes into the cabin. We walked on our originating aircraft to the strongest odor of noxious fumes. The forward service door as well as both the aft service and entry doors were opened to allow some of the odor to dissipate. We informed our Captain (who was not present when the Operations Supervisor told us what had happened) that the smell was too strong to board at our scheduled time. He was upset that we would 'delay the flight'; but we felt this was best for the safety and comfort of our passengers. We waited approximately 15 minutes to board as we thought some of the odor has dissipated. We pushed 5 minutes early and arrived 25 minutes ahead of schedule. By the end of that first flight; I was feeling nauseous. The 'C' FA mentioned she was beginning to get a severe headache.When the ground crew was provisioning our galleys both mentioned the strong smell of gas when they came onboard. The smell had not gotten better; we had merely gotten used to the smell.[Later in the day] one of the outbound pilots mentioned the strong smell when he came onboard. Four hours after the initial discovery; the smell was still present. All 3 of us FAs had felt its presence; whether it was nausea or headaches.


Synopsis: B737-700 flight attendants reported feeling ill after departing in an aircraft that had a heater cart blowing exhaust into the cabin for some time before departure.