I’ve seen in some fanfics that Izuku can use Gearshift to make fire and ice my speeding up molecules. Now, I don’t think he can do that, but perhaps if you combine Gearshift and Half Cold Half Hot?
This Emitter type Quirk allows the user to speed up or slow down water molecules with a medium range of themselves. In effect, this lets the user control the state of the water molecules. This can be anywhere to making it cold as blue ice to making it hot enough to burst into flames. This can effect small droplets of water to whole swimming pools worth of it. The user can change the state regardless of what it is, like changing fog to ice. The user minor control over where these molecules move, such as making boiling water fly out to hit someone. This gives the user an immensely versatile Quirk, drastically altering the battlefield with their numerous elements under their control. They can form ice around their enemies to block them, suddenly make bursts of flames, covers areas with fog to hide themselves, blast themselves around with bursts of steam, shape the water in advantageous ways, counter act certain water based abilities, or just make sure their water is just the right temperature. Though the Quirk works best with some sources of water around the user to work with, so random droplets won't have amazing effects. The user has a harder time interacting with living resources of water, such as people. So they can target sweat on people's bodies, but they can't make people's bodies boil.