The Doctor was fussing with controls when there was a thud under it (where there was a collection of old and new things hidden), and something like muffled sobbing followed. He climbed under it and saw that his little charge Johnny-Jimmy was supine on the bottom of the "clothing chest", in a pile of old hats.
"For how many times I've told you not to climb on things?" It was clear that the child (he was only one year old and still couldn't walk properly) had been trying to reach to the bright-red spot - obviously the fez - but hadn't managed to hold himself on the floor and had fallen into the opened hatch. Luckily he wasn't too hurt... or was he? A huge purple bruise was about to emerge under Johnny-Jimmy's eye.
"Sowwy, Dotta-daddy!" the child squeaked, curling up in a little ball, as if the Doctor was going to hit him. "I sowwy!"
"Understand, JJ, I'm not going to shout at you. I tell you not to do such things because I am afraid to lose you". The Doctor scooped the boy up and examined the hurt place under his eye. "Does it hurt much?"
"Wee", Johnny-Jimmy replied, sniffing.
"Hold still". The Doctor's fingertips brushed over the hurt patch, letting a teeny weeny bit of regeneration energy come out and make the potential injury vanish. "That's it. Was that painful?"
Johnny-Jimmy shook his tousled blond head.
"Promise that you won't do that again. If you need something, ask me, okay? You promise?"
"Pwomiss!" the boy said solemnly, wrinkling a bit - the healing hasn't been completed yet. Completely sure that now everything was fine, the Doctor lightly kissed Johnny-Jimmy's cheek - that was a universal healing against children's injuries in all times.
A/N: The Doctor + little children = lots of "awwws", at least for me. I thought it would be nice if - some time - a little child became his companion.