An air ambulance made a landing near the courts of law in Spinningfields as paramedics were scrambled to the scene.
The helicopter landed on top of a building in the city centre area, while two ambulances pulled up on King Street West.
It was later seen taking off again, with one onlooker telling the Manchester Evening News: "It was on the roof of a corrugated car park, the building underneath was called 'Elite'.
"It looked serious with two ambulances on the road as well."
North West Ambulance Service (NWAS) have since confirmed they were responding to someone who had 'fallen ill' in the area.
The person was taken to hospital by ambulance.
A spokesman from NWAS said: "We responded to a medical incident on an address on King Street West.
"Attending were two ambulances, an advanced paramedic, and an air ambulance.
"The patient was taken to hospital by road."
It has been a challenging summer for NWAS, which last week moved to 'REAP 4' - indicating extreme pressure - amid reports of '14 ambulances' queuing outside Stepping Hill's Emergency Department and patients waiting up to 18 hours for a response.
