Air carrier Flight Attendant reported the cabin was uncomfortably warm in flight. The smoke detectors went off; a strong odor filled the aircraft; and the flight crew performed an air turnback.

Narrative

At briefing we told the Captain that the cabin was really warm. The Captain stated that the APU was just turned on. At boarding we contacted the Purser/Captain on the ground; a passenger was complaining that the area was unbearably warm in the area between Row XX - YY. After takeoff; the area did not cool off as expected so I spoke with Captain about angry passengers in Seats XXC; XYC and XZA. He told me that he would call Dispatch to inquire what to do about proceeding to ZZZZ. We continued with our inflight service. About halfway into the service the crew bunk smoke detectors at 3L and 3R went off. A Flight Attendant inspected the crew bunks at Door 3L and 3R and found no signs of fire while other flight attendants called Purser and Captain. Business class had a very strong and distinct bandage smell or dirty gym sock smell. The smell wasn't present in coach until final descent and was through the whole aircraft. I developed watery eyes; congestion; and tightness in my chest. We returned to ZZZ and arrived at the gate with personnel meeting the plane. At the Captain's advisement the flight attendants sought medical attention.