"You see that patch there, where that wee bit of smoke is?" he asks.
"It might not look that bad, it might look like it's almost out. But that's so hot you could cook a hangi under there in no time.
'We're going to have to get in there with shovels and dig it out."
That spot sums up much of the Port Hills - charred and smokey on the top but smouldering hot and extremely dangerous under that top layer.
It's not over up there, far from it, and the crews on foot doing the hardest yards of the fire fighting mission - the men and women turning over every bush and inspecting every crevice, nook and cranny of the hills by hand know it.
The Herald was taken up to the fire line, a 26km stretch of the hills with a fire fighter hosing, digging or checking every few metres, to see not only the extent of the inferno but the ongoing and massive effort to control it.
Molten embers still simmer away under the charred black top layer, and a good dust of wind could pick them up, send them flying and create another fiery hell up there.
The rain didn't really help - all that did was throw a dusting of greasy water over the top, a layer that would only take 20 minutes to dry if the wind picked up.
"It's like spitting on a barbecue, it does nothing really, " Rural Fire Service sector boss Phil Crutchley said.
His crews have been working long shifts - 15, 16 or 17 hours up in the hills at a time. Their faces are blackened and their uniforms covered in a mixture of mud, soot, ash and sweat.
It's been a big week for them, but at no point have any of them wanted to chuck it in, go home.
"Everyone is sticking together, it's our job and it's got to be done so we will keep soldiering on," one fire fighter said.
Everyone up there will tell you that Tuesday was the hardest day. Wednesday had the biggest and most intense flames, did the most damage to properties and the land. But Tuesday was tragic.
Helicopter pilot Steve Askin was killed when his chopper went down on the hill.
The fire fighters had lost one of their number - and the shock and pain was palpable.
Incident Controller Richard McNamara said the crews, in the air and on the ground, were devastated, shell shocked.
"My job is to pull that back together, to get them concentrating on what was needed," he said.
McNamara told the crews that if anyone needed time out they could go home - they'd lost a comrade, a mate and if they weren't up to flying or fighting the flames on foot he encouraged them to take some time out.
No one did.
"To lose one of our number is devastating," he said.
"We had to continue fighting this fire while the crashed aircraft was on the side on the hill... the guys had to fly over it. Can you imagine what that must have felt like?
"The helicopter pilots are a tight group. They all work for different companies and there's competition there of course, but when it comes to fighting fires - they are tight.
"I said they could go home but none of them would. It's devastating, but they said 'the only way we could pay out respects to Steve was to keep doing our job.
"It still hurts, there is still a lot of grief, but the only little thing we can do is tell his family we carried on because that is what Steve would have done," McNamara said.
The fire line is broken into segments with a crew assigned to each. Before the rain they walked their patch, spotting smoke and hosing areas down or digging them over, the fresh soil underneath smothering the burning embers.
Now though, they have to physically inspect every inch to make sure they haven't missed a single spark.
Once the area is checked and the sector boss is happy that it's all doused and no longer poses danger, they move on to the next.
When the Herald visited the area it was quiet, almost peaceful. Every few metres a fire fighter could be spotted off the muddy track, hose in hand constantly searching, spotting, spraying.
Wisps of smoke wafted up from the black charred remains of the pines that once stood proudly on the Port Hills, the sound of running water from the hoses a foreign one up there.
Much of the terrain is steeply slope and Crutchly explained this made it easier for the fire to spread.
For example, on a 30 degree slope the fire could cover 6000m in a single hour. Throwing water at it was useless, the crews had to start at the bottom and work their way up, killing it off at the roots to stop it flaring up again later.
They call it the "base and chase" and they anchor themselves at a point and follow the fire upwards.
It's hard work and much of it is misunderstood by the public.
Fire fighting is not a case of turning on a hose or choppering in a bucket of water and dumping it.
It's a game of strategy and attack, a game that is not necessarily focused on the flames.
That was made very clear on Tuesday night when the fire was at its peak. Two giant smoke columns had forms and they were building in energy and height.
The choppers were pulled out, the crews were pulled in and everyone watched and waited.
There has been a lot of criticism around that and a perception that the crews didn't do enough, didn't do things right or properly, let the fire go too far.
Houses were lost, others were damaged. It was torture for the residents to watch.
But neither Crutchley or McNamara apologise for that. They had a job to do, they were doing it, and both are 100 per cent clear and satisfied they did the right thing.
"We had to pull back because it was just too dangerous," Crutchley said.
"When it gets like that, there is nothing you can do - at all - that will stop it.
"It's life first - our lives. Property, you can replace but you can't replace lives."
McNamara said he "will go to the grave" knowing the crews did everything and anything they could to stop the fire, save houses and keep Christchurch safe.
"That fire had the energy of a couple of atom bombs - you just can't control that," he said.
One of the team working up the hill when the Herald visited hadn't seen his family since Wednesday when they were evacuated from their home.
Asipeli Osai is a City Care fire fighter and he was on the end of a hose dampening a pretty ominous looking hot spot when the Herald visited.
He was reluctant to let it go, he seemed almost distressed to have to stop work for even a moment to speak to us.
But his mates assured him, took the hose from his hands and told him to take five.
"We've got this matey, you're all good," one said.
Osai relinquished his grip on the hose and stepped aside. He looked tired, his face smudged with the inferno's residue, but determined and alert.
He was at home for a bit on Wednesday and popped out to pick up his daughter. When he got back the police were there, the street had been evacuated and he had to go.
"I didn't have a chance to go back, to get anything," he said.
"I don't know if my house is still there."
Osai wants to get home, but he wants to fight the fire more. It's not just his job, it's his duty.
"There is nothing I can do at my house, but I can come here every day and help," he said.