B737-800 flight reported aircraft encountered engine overheat warning inflight.

Attributes
ACN	1742820
Time
Date	202005
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Climb
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 100 Flight Crew Type 2400
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Other / Unknown

Narrative:

On climbout at about 16;000 feet to 18;000 feet; we saw a master caution light with an ovht/det (overheat/detection) message on the recall. As we were evaluating where that was coming from; we had a fire bell and lights come on intermittently. We asked ATC to level off to troubleshoot. We cancelled the bell and tried to assess where the ovht was coming from and if there was a fire. We [advised ATC] and turned back to ZZZ and continued with the engine ovht qrc/QRH (engine overheat quick referenece checklist/quick reference handbook) as the lights and bells all ceased; there were no secondary indications of an engine fire and we thought the ENG2 overheat was illuminated. We completed the diversion checklist and all the other necessary checklists and landed at ZZZ.

Original NASA ASRS Text

Title: B737-800 flight reported aircraft encountered Engine Overheat Warning inflight.

Narrative: On climbout at about 16;000 feet to 18;000 feet; we saw a Master Caution light with an OVHT/DET (Overheat/Detection) message on the recall. As we were evaluating where that was coming from; we had a fire bell and lights come on intermittently. We asked ATC to level off to troubleshoot. We cancelled the bell and tried to assess where the OVHT was coming from and if there was a fire. We [advised ATC] and turned back to ZZZ and continued with the ENG OVHT QRC/QRH (Engine Overheat Quick Referenece checklist/Quick Reference Handbook) as the lights and bells all ceased; there were no secondary indications of an engine fire and we thought the ENG2 OVERHEAT was illuminated. We completed the Diversion Checklist and all the other necessary checklists and landed at ZZZ.

Data retrieved from NASA's ASRS site 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.