something like these https://www.primark.com/en-gb/p/thinsulate-knitted-gloves-bl.... The particular ones I have also seem to work somewhat on touchscreens which is useful for the commute home

This works even when my hands are the only part of my body that feel cold. The body is effectively prioritizing keeping my core warm instead of the extremities, so adding insulation to the body has the trickle-down effect of warming the hands. On the other hand, trying to warm just the hands never feels like enough.