"Wait are these dudes immortal."

"Yep."

We do not experience that, no. I expect the war to be over in fifty Years but I am not sure if our years are the same as yours.

"Well, how long are yours? ...How do you even have 'years' without a sun?"

The Valar count them. A year in your world is related to the Sun? A year for us is twelve times twelve times twelve days. 

"That's a lot longer than our years even if your days are somewhat shorter. Ours are Sun-based, yes, as are our days... we've been here maybe an hour to the extent I can rely on my internal clock, a day is twenty-four hours, and a year is three hundred and sixty-five days, divided into five seventy-two-day quintiles and five changedays for convenience."

Our days were by the Trees, and the Trees are absent, but they'd be - perhaps longer than yours? We don't generally subdivide them. You might die very soon by our standards. I wonder if I can do anything about that.

"Well, that'd be nice, at least if I can expect to ever go home. It'd probably be irresponsible of me to become immortal if I can't."

Because of the powers, right. Okay. I won't make it a priority if you don't want it. We have a lot of priorities as it stands.

"Oh, I want it like crazy, but not at the expense of my country's stability, and I don't have a way to assess that from here."

"My country's stability - depends on crossing the Ice quickly."

"It sounds like I can help with that if the problem is mostly something that can be solved by stuff being warmer."

"It happens to be a problem that can mostly be solved by stuff being warmer, yes. How fast can you make stuff warmer?"

"...Instantly? If it's in range? I might have some limit, I haven't tried making a volcano in my backyard or anything, but by and large anything in range I'm paying attention to is a temperature I find satisfactory moment to moment."

"Great. In that case we might in fact be able to win the war fast enough to get you home on mortal time."

"That would be nice."

"Are there minimums? Maximums? If you find it satisfactory for the Enemy to be true-frozen, the temperature at which no molecules move, could you do that?"

"I don't know. I don't have any limits I have run into but have not attempted particularly rigorous experiments because I'm risk-averse, primes can and do die screwing around with our powers, and I'm a very busy person."

"Okay. I think this is a cause worth risking your life for, though obviously we shall do everything in our power to minimize the risk. The Enemy creates people magically bound to obey him and in constant torment, from birth which he uses to disfigure them. There are hundreds of thousands of them and there will be more if we delay."

"Yes, that sounds like a serious problem all right."

"He also gets stronger with time and will eventually destroy the whole of the world outside Valinor if we do not stop him."

"Also bad, yes."

"So let's start melting and refreezing this ice into a path."

"I'm told I don't have to actually walk it? I am unreliable at walking even on friendlier surfaces than ice."

"We're working on sledges as we speak, and can in any event carry you."