I take spare shin pads, a pump, insulation tape in 7 different colours, a first aid kit, two pairs of pliers for removing jewellery (I kid you not), pegs for nets, a pressure gauge, three tops of different colours, pencils, pens, cards, coins, a cheap Casio watch (in addition to the watches I wear) and several different whistles.
There's loads of things that aren't my responsibility I like to have covered anyway so the game can go ahead.
For cold legs have a pair of Icebreaker merino wool undershorts. They are £40 but worth every penny on a cold day. (That's slightly more than one match fee.)