B737-800
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Physiological - Other
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Flight Cancelled / Delayed; General Physical Injury / Incapacitation
Aircraft
While boarding the aircraft and walking halfway down the jetbridge; a very strong electrical/oil burning smell could be sensed emitting from inside the cabin of the aircraft.  I asked the flight attendants if they could smell anything and they all acknowledged the strong odor.  I called Maintenance and made an entry in the aircraft's AML describing the discrepancy.  The packs and recirculating fans were turned off and the odor remained present throughout the cabin. Main cabin door and galley doors were open to get cross ventilation and odor remained. The strong odor was later verified by a Maintenance Technician and the Agent working the flight. Within a few minutes the entire crew exhibited discomfort symptoms of lightheadedness; headaches; nausea and watery eyes. The First Officer was not present since he had been reassigned to a different trip. The new First Officer was in transit and not present when the event occurred. I removed the crew from the aircraft for further assessment. In the interest of safety; it was decided to have the crew assessed by medical personnel. Company medical was closed and the other alternative was the hospital. I advised Dispatch; Operations; base chiefs and crew tracking of the event and pending medical assessment. I was tested with an arterial blood test (hurt like a bugger) to determine the CO2 levels in my system. All crew members were eventually discharged with the proviso to seek further medical attention if further symptoms were noted.
B737-800 Captain reported a burning smell emitting from the aircraft while boarding. The Captain and cabin crew were removed from the aircraft for medical assessment.