I’m probably extremly late for the party on this one but thought I would share it anyway – sourced by digging through my new guild forums
It’s a Face book Application ( see you can’t escape from it’s clutches) Penetrating Cold Simulator that is for healers to get practise at keeping one target alive during penetrating cold on Anub
I was expecting to need to keep all the marked targets alive, but your target is the only one you need to heal – so the challange for 180 sec is to keep the changing “Heal this target icon” alive – this changes approx every 30 secs.
My target only died to lag. I swear.
There’s only one spell you can cast, and one target. So it’s more like a priest going Flash Flash Flash Flash! where in reality it probably would be Flash Flash renew – Hit them with a POM, and a COH in varying intervels.
But if your bored and you want to heal green bars for fun, or your need practise left clicking
Edit – Because I am aware of the overhealing mechanics on Anub 
( in before the comments correct me reality is on the TOG’s I’ve healed is keeping renew up on the targets – flashing when they need a top up, but if course keep them low. I’ve only healed a 10 TOGC + the normal 10/25 and that was stressful. Would hate to be a healer on a TOGC 25
Provided by 
ToGC isn’t that bad as a priest. Just spec Discipline. PWS target 1, Penance target 2, Flash Heal target 1, Flash heal target 2, keepp repeating steps 3 and 4 until the 18 seconds are over.
The PC does 6k damage, but after resistances it does right around 5.5k damage every 3 seconds. Which means you can Flash Heal two targets just perfectly. Only reason to use PWS and Penance at the beginning is for reaction-time in identifying the target.