Heating the Resistance Base was clearly out of the question. The energy needed for such a task was more than what Ciel was willing to risk, not to mention such energy consumption would have been deemed wasteful by more than a few people. The Reploids could deal with it well enough, with their cores providing enough energy to heat their extremities moderately well, but Ciel's case was different. Being human, and a small one at that, she was forced to bundle up, with layer upon layer of clothing, and subsequently endure the freezing temperatures. Even her room was not safe. She never once complained though, and took it all in stride.
Well, almost all of it.
The nights were noticeably colder, and in turn more difficult for her to deal with, and being both cold and tired tend to make humans more irritable than normal, something Zero had recently come to learn. Quite quickly in fact; but speaking more softly and slowly could only do so much. What she really needed was a good night's sleep, and multiple nights at that. What bedspreads she had were not necessarily what you could call warm, not to mention they were in desperate need of repair, but who had the time for that while in the middle of a war? At least, that was Ciel's excuse. Zero had taken the opportunity to point out that if that was the case, then this was no time to knit people presents either.
The blush that had promptly colored her face nearly outmatched his armor, and was immediately followed by a loud sneeze. Taking it as his cue, Zero took the opportunity to hoist the girl from her seated position at her desk, and promptly deposited her in the massive pile of blankets that had once been her bed. In any other situation, the look of utter shock on her face would have given him cause to smile, but Zero had a more pressing task at hand.
Unceremoniously climbing into the bed himself, he then proceeded to sort through myriad of blankets in an attempt to find the ones that looked the warmest. Once satisfied, he attempted to construct a large enough… cocoon for the both of them to fit in. After much more fretting than necessary however, he finally succeeded, albeit with Ciel's help. Ultimately, Ciel had taken up residence in Zero's lap, with the majority of the actual heating being done by the Reploid's core.
Ciel was against the concept at first, but eventually gave in to the substantial amount of warmth Zero was providing.
Zero was practically the picture of triumph, with Ciel's amusement poorly concealed. She had commented he reminded her of an overly protective cat, which he responded to with a indignant frown. After all, what good was he if he could not even protect her from the cold?