B787 First Officer reported smoke and cargo heat indications resulted in a diversion. First Officer noted the lack of a checklist for cargo heat bulk warning.

Narrative

Altitude- FL400Airspeed- 0.84Indications- SMOKE REST UPR DR 4 & CARGO HEAT BULK. Initiated R5 Offset. Ran SMOKE REST UPR DR 4 checklist - No smoke reported by Flight Attendants (FA) who heard and reacted to the smoke detector alarm in the FA crew rest area when the detector sounded. Picked ZZZZ for potential divert location. A short time later got CARGO HEAT BULK EICAS. Summoned First Officer (FO) from break. There was no EICAS checklist for Cargo Heat Bulk. Only a FM non normal titled CARGO HEAT BULK; forward which was referenced. FA called from door 4 saying the floor was extremely hot in aft right galley area. Selected direct ZZZZ while in process of offsetting track R5 and began direct path to ZZZZ while descending to FL395. Weather verified as acceptable urgent divert to ZZZZ by FO. Sent CPDLC ATC EMER Message and remained at FL395 proceeding direct ZZZZ. Changed with FO from Control Seat to Center jump seat. [Center] via CPDLC sent two messages of potential opposite direction traffic altitude conflicts. Stayed at FL395 until voice contact with ATC who coordinated descent to lower altitude with routing to ZZZZ. Passenger Announcement made by me to passengers to inform reason (Smoke warning in FA rest area which was verified as no actual smoke in area and Cargo Heat indication which was still under investigation); currently diverting to ZZZZ for turn they had observed on flight progress screens in the cabin - there were a lot of passenger inquiries to the FAs asking what was happening. Called FAs and exchanged information. Asked FM to have FA located at door 4 to call me. Door 4 FA called me back to describe floor temperature in aft right galley located directly next to Door 4 right and aft; the hot area of the floor was below the aft portion of the slide and rear wards of it to the bulkhead; approximately 2-3 square feet of surface area- it was hotter than normal and hotter than the floor forward of the hot spot. Instructed her to monitor temp of hot area and keep me updated especially so if the feel of heat increased. Pre-briefed with Captain (CA) regarding briefing task with FAs. Then called FM and conducted brief. Spins included don't expect an evacuation but review anyway. Recovery; Approach and landing at ZZZZ was uneventful other than maintaining fast forward airspeed for as long as possible. Stopped on runway while Airport Rescue and Firefighting (ARFF) inspected entire aircraft with particular attention to Aft Cargo and Bulk Cargo bays - they opened both doors to accomplish visual inspections of the bays. Nothing abnormal reported by ARFF. Taxied clear and parked using guidance of follow me truck. Extensive CRM debrief conducted with cockpit crew first then entire cabin crew.