When Kíli was little, he felt the cold badly.
His mother even joked that when he was birthed; he came out 'shaking and shivering instead of crying'. He didn't know why he felt it as badly as he did, no one else did. His friends would be playing in the snow, shaping weapons on the ground with only thin clothing on while he was shivering with three layers on. He would watch Fíli play with his friends and fight and have fun and would want to join in but couldn't find the strength to run let alone stand up with the cold overpowering his limbs.
Fíli knew about his brother's affliction. It pained him to see his little brother wither away from social events because of the weather, but it hurt him more when he used to watch Kíli tremor in his bed at night until he his body was too weak to retain consciousness and sleep consumed him.
It was one night when winter hit Erebor and Dale badly, snow suffocating the land with its cold grip, when he knew his brother would not cope through the night. Their mother had suggested that Kíli should sleep near the fire that night but the stubborn dwarfling refused and denied feeling any chill at all. But he soon learned that his brave demeanour would fade when the night only continued to decline in temperature.
Teeth chattering, body shaking, little whimpers barely escaping his throat; Fíli couldn't stand to see his Kíli in pain anymore. He grew tired of listening to his brother's teeth chink loudly every winter. He threw his blanket off his small body and stomped over to Kíli's bed, a little annoyed that his shivering was keeping him awake, and grabbed hold of his little brother's hand.
"Fee?" Kíli questioned, reading his brother body language quite fast.
"Come with me."
Taking the blanket with him, Kíli followed the blonde dwarf over back to his bed, still shaking and sleepy as he quickly wrapped his blanket around his shoulders. He stood at the edge of the bed, watching Fíli climb back into bed and turn away from him, dropping his hand.
"Climb in brother. I am tired and your teeth are keeping me awake."
Kíli did not reply; he stood there, worrying his bottom lip between his teeth to make them stop.
Fíli waited for his brother to answer him, waiting for the bed to dip and to feel his back against his own. It was not that foreign to them to share a bed; they had done so many a time whilst camping with Uncle or just playing around outside.
But still, moments passed and yet there was no dip, no cold skin against his own warm skin.
Fíli opened his eyes, rolling his eyes at the wall in front of him and turned back around, propping himself up on an arm, and looks straight into Kíli's watering eyes.
"Kíli…"
"I'm sorry!" Kíli sniffs, an arm coming up to wipe the tears away with his blanket, "I don't mean to keep you away from your dreams every night. I don't know why I am cursed with feeling this cold all the time!" He blinks away more tears, body shaking from both the cold and emotions.
Suddenly all anger towards his brother was lost when his eyes track the tears falling down Kíli's young cheeks. Slowly, he reached for the small hand again, and began to pull Kíli into his bed. He pulled him right into his space, tucking Kíli's head under his chin and lets him cry a little more until the shaking is only from the cold and not from his crying.
"Wait here a moment." Fíli said quietly, quickly jumping out of bed and rushed over to his drawers to pull out something to which Kíli couldn't really see due to the darkness in their bedroom.
He watched Fíli's body come up, jump over his body and slide back under the covers. He placed something heavy over their bodies.
Kíli felt a tickle of something under his chin and takes a deep breath in, turning his head to get a better look at the heavy item over their bodies. He eyes widen a little as he recognises the smell and weight of the clothing.
"This is Father's…" Kíli muttered, letting go of the grip he was holding on his blanket to run his small fingers over the golden fur covering the collar of the coat.
"Mother said that father left for us, to remember him by. I sometimes wear it if I feel saddened by someone's words or just by his absence in my life. It makes me feel safe." Fíli explains, watching the younger dwarf look over the coat in reverence, "just know that even though I may feel the anger more powerful than Aulë at times because of you, you are still my brother and I will always look to protect you."
Kíli stopped petting the fur on the coat and looked at his brother, his eyes still rimmed with redness, and smiled weakly, drawing his hand back under the covers and closed his eyes, letting Fíli pull him in once again. Soon, sleep washed over their bodies and Fíli fell asleep knowing that his brother was warm and loved.
Soon, that was the only way Kíli could fall asleep when they were younger. It first started with him crawling silently into his other brother's bed at night, curling into the warmer body to gain a good night's sleep. Then it turned into Fíli falling into bed with Kíli following him, not even waiting for an invitation. It turned into a habit that neither brother felt was wrong. Fíli grew accustomed with the feel of his brother close to his back or chest, even in the warmer times of the year.
Some nights, Kíli would drag their fathers coat into bed with him, finding that the weight of the coat made him feel protected. But as the months followed, the coat was not needed anymore and it was just the warmth of Fíli's body that protected him.
The heavy arm over his body, the warm breath on the back of his neck, the knowledge that Fíli would always be there for him; Kíli knew, even though he was young, that he needed his brother more than he would ever let on.