Air Taxi helicopter Captain reported experiencing high oil temperature on one of the engines during cruise flight; resulting in the Captain diverting to another airport where they landed safely.

Narrative

At approximately 5 minutes from arrival at the receiving hospital with a patient on board; I looked down and noticed that the #2 Engine oil temperature was high and exceeding limits in the red range at 142 degrees C. There are no other indications or cautions in this model of an ACFT that would alert us to this type of malfunction. I informed the crew that we were having an engine malfunction and attempted to increase our airspeed to see if the temperature would come down. There was no change to the temperature so I established parameters and slowed down to 100 knots; then identified the malfunctioning engine and brought it down to IDLE. I told the crew that we would be diverting to the ZZZ which is about X miles away from the receiving hospital. They acknowledged and began contacting Aircom to coordinate getting a ground ambulance for the patient. I contacted ZZZ tower and Requested Priority Handling due to an engine malfunction. They proceeded to clear out the traffic pattern for us. We were lined up at this point on about a 5 mile final to runway XX. I requested we land on runway XX and tower stated that we could land wherever we wanted. I also requested to have crash rescue close by after landing; which they did. After about 15-20 seconds upon bringing the engine to IDLE I checked the temperature to see if it was coming down at all. It was not so I proceeded to perform an engine shutdown on the #2 engine. We continued for runway XX and prepared for a run on landing. On short final about 50 feet above the runway I brought the #1 engine to 125% or so with a shallow approach and allowed it to settle in for a run on landing with about a 10 foot slide. Upon landing I proceeded to complete the shutdown of the aircraft and informed the crew they could exit to get the patient ready for ground transport. An ambulance arrived at the aircraft a few minutes later and the medical crew completed the transport by ground. No injuries or aircraft damage (apart from maybe some new scrapes on the skid shoes) occurred as a result of this.