(A/N: This is with thanks to TalkingLollipop who requested it)
Tooth was zooming around the French beach happily. The sun beat down upon her feathered wings, and even North was enjoying himself as he constructed a large and magnificent sand-castle, which he seemed to be having fun with. Bunny was off in one of the caves, exploring, while Sandy was as expected happily crafting huge sculptures out of his usual substance, bar the usual qualities.
And where was the Guardian of Fun?
He was hunched under an umbrella, seemingly staying still. He grumpily refused any invitation to join in, saying he was busy.
Tooth sighed and looked over, seeing him nestle his head in his arms like an unhappy child. Jack would usually be having the most fun, so what on earth could be wrong?
...
Jack felt like his blood was burning as he inwardly whined. Nothing was cold nearby, not even the cave, and he felt like everything was too uncomfortably warm to concentrate. Small gasps left his lips as the heat continued to badger and discomfort him and he growled at any invitation to step further out into the horrible heat of the sun - the big ball of gas up in the sky most definitely had it in for him.
He was beginning to go through swirling dizziness, coughing a little as his head spun.
...
Bunny looked over to the umbrella in time to see Jack fall on his side, racing towards him. "Frostbite! What the hell is you with ya?" he asked, before noticing Jack's shallow breathing and uncharacteristically red cheeks. He quickly put his paw against the boy's forehead, and scooped him up immediately.
"We gotta get back! Frostbite's feverish!"
...
Jack woke in the thankfully cold infirmary, sighing. He could hear someone outside with a soft and calming voice that made him feel like he was a young kid again.
"Jack is a form of winter, he cannot deal with too much heat for too long. He goes to icy places when he needs to be alone...He just won't really be able to deal with warmth too much. Fires, fine. Overly sunny places, not so fine."
"But...Mother Nature, he agreed to it!" Tooth pointed out, seeming a little surprised, Mother Nature sighed. "He didn't know, most likely. Please watch over him for now."
He sat up, and started to make his way towards the door. Time to meet the mother of the seasons...