We searched the area to see if we could find its mom or any other kittens, with no luck. There was a construction helmet sitting on the ground nearby, so I placed the kitten in it so I could take it home. The little one meowed almost the whole way back, and was clearly distressed.
I got home and messaged a few people who own cats, but no one had dealt with such a young kitten - it wasn't even weened off its mother. I learned that cow's milk would not be good for it, and I had nothing else in my apartment to feed it. The stores were closed since it was late, so I had to hope it would make it through the night so I could take it to the vet in the morning. I arranged a towel in a drawer and it spent the night there in my living room so the meowing wouldn't bother me or my flatmate. We also named it Meo (Vietnamese for cat) before going to bed. Here it is next to my hand for comparison:
The following morning the kitten was fine, though surely very hungry. I packed her (I think it was a her) into a backpack, along with a hand towel for cushion, for the drive to the vet in District 2.