The only reason Xolotl had looked tense after Tezcatlipoca hissed at him like a tyre with the air escaping was because Quetzalcoatl had been right, he really should have been in bed. He'd far past overexerted himself and he heard his brother and the other Aztec without hearing them, as though they were faint and far off.
He sighed even with his brother's hand on his shoulder, said 'oh' softly like something mildly surprising had just happened to him and then his legs rebelled and he sank down to the floor, not quite as dramatic as a collapse but not too gracefully either, clearly something he couldn't control. The next thing Xolotl knew he was sitting on the cold floor of the museum and he shivered as the cold inside him bled out into it.