Even after being a student at RMI for three years, Malachi was still always entranced by the snow the school would get from time to time (even if he really favored warmer climates). Especially on Pearl Street, when it was lining the rooftops, or untouched on the Quidditch Pitch. It looked so peaceful, and soft.
Except it wasn't. It was very cold, and if you fell on packed snow (which he'd learned the hard way after trying to make snow angels in his third year), it was going to hurt.
Still though, Mal thought it might be fun to get out and do something, so he'd thrown on his puffiest, warmest jacket, a hat, scarf, gloves and mittens, and two pairs of socks under his boots. Yes, he looked very overdressed for mild winter weather, but Malachi did not like to be cold.
When he'd noticed the big hill of snow, he realized that he really didn't know what it was about. And then he saw the sleds. So, he began to trek the climb up the hill, determined to try something new. At one point, he began to slip back down the hill (it was kind of like walking up a sand dune. He'd done that on a vacation with Bianca and it left him very tired and his legs hurting) and so on instinct, he grabbed out at the thing closest to him--another human's leg.
Which meant that Mal was bringing this person down with him.