"That makes a lot of sense and we can certainly give it a try. Also, in my experience naps aren't a bad idea in general; if you're having trouble as a result, you might just need shorter naps or to fit them in earlier, maybe right after lunch. What time do you tend to nap now and for how long?" 

"Right after lunch, generally, and until I wake up on my own, unless I'm worried I'll sleep through something and ask Yfandes to wake me up."

"You could try asking her to wake you up twenty or thirty minutes after you fall asleep? Might have to test what interval has you waking up not too groggy, but even twenty minutes should help a lot with focus for the rest of the day, without risking insomnia that night like a two-hour nap would." 

"That's definitely worth trying, thanks."

"Anything else for today?" 

"No, I think that's everything."

That evening, he gets out a notebook, and starts writing an entry each day with all the things he's supposed to do and space to mark whether he did them or not, plus a note on how well he slept each night. He remembers the past few days well enough to fill them in retroactively; going forward he'll be able to see objectively whether he's making progress or not.

And then at the appointed time, Savil can collect him to ride out for their weather-barrier explosion testing. 

The four of them riding along the river is nice and relaxing, even though he's possibly about to start a massive fire.

Eventually they come to a place where there's a wide, calm stretch of water with nothing and nobody flammable nearby.

"I'm going to set up some precautions just in case," Savil says, carefully casting a cylindrical mage-barrier that hovers just above the surface of the water and wraps around, covering the width of the river but protecting the flammable plants around the shoreline. "All right. Ready, I think." 

"Okay. Here goes." He starts with the smallest weather-barrier he can manage, only a foot or two across, and pulls heat from the water into the spherical shield in a steady stream, counting seconds in his head.

At ten seconds, ice is forming on the surface of the river, the air above it going foggy with the sudden chill. At twenty, the air inside the weather-barrier is glowing. But still not doing the thing, yet. At thirty the thickening ice reaches the banks and it's taking noticeably more effort to keep the weather-barrier container in place. 

At thirty-five seconds the thing happens and suddenly the air inside the barrier seems to itself be on fire, heat coming from nowhere–

Abras takes two seconds to stare at the phenomenon with both regular eyes and Mage-Sight and then undoes it, stopping the heat transfer and releasing the energy to splash against Savil's barrier-shield.

"Wow. Okay, looks like it can happen at a small scale too."

"That's both fascinating and kind of scary," Savil says. "Hmm. I'm trying to think if there's anything else about it we should test, while we're out here, but I'm stumped. You got ideas?" 

"We could try doing the opposite thing, a really big weather-barrier with the same total amount of heat as the small one. If that doesn't explode we'll know it's about the density, but, uh, it might explode."

"Hmm." Savil thinks for a minute or so. "...I think we can do it safely. I could kind of see the change, when it happened - if I see it happening again I'll give it a good shove upward and it ought to mostly just scare some birds. You think you can manage a steady rate of energy into it, that's the same as before even though the barrier is bigger?" 

"I think so. I was paying attention to the rate the previous time, I think I know what it would feel like to match it and if I notice I'm not I'll stop and we can start over."

"All right. Let me just reinforce the barrier-shield around it a bit and then we'll give this a go." Savil takes around a minute at it, weaving the magic even tighter, not that it really took any damage from the smaller heat-splash. "Ready." 

He starts up again, paying careful attention to how fast he's transferring the heat and counting seconds again until he gets to the same amount of time it took to do the thing in the smaller space, then stopping the heat transfer without undoing the shield.

It's hot in there, enough for the air to be glowing slightly like it does near a flame, but it's not making more heat come from nowhere. 

"If we'd been thinking," Savil says, "we could've moved a ways upstream so that we could also see if it made the same amount of ice on the water. But I was watching your energy-channeling and it did seem to match. So it does look like it's about the density, not just the total."

"That would have been a good check, yeah, but it looked like a good match to me too. Now I'm wondering if there's any way to do something with the energy when I undo it--like pulling the energy from a shield back into my reserves, except there isn't an equivalent of reserves for heat because it isn't turning into anything, so maybe that's stupid."

"Huh! What an interesting thought." She chuckles. "I feel like the equivalent of reserves for heat is - firewood, or oil, or something. The thing that makes the heat. Only, you can't turn a fire back into wood either." 

"Yeah, exactly--oh, but I could try putting the heat smoothly back into the ice instead of just letting it go. And then if I can keep going after that it would be like your reverse weather-barrier idea for cooling an area."

"Huh! That's an idea. Want to try it now?" 

"Sure." He sets to doing it. It's a bit like trying to speak while inhaling, and he has a bunch of fumbling and false starts, but he can tell it's possible in principle and eventually he gets the heat going fairly steadily the other way.