In the old days during winter, we used to put our lunch boxes on the school stove (so-called bento)

Before winter break started..
Around November, I think..
About an hour before lunchtime, we would place our lunch boxes on the wood-burning stoves or something similar.
(Some kids were even sent to help the school staff gather wood, haha)
Nowadays, doing that would be considered a huge inconvenience.
People would probably file complaints asking why lunch boxes are being left on stoves to make the place smell... (assuming there were even stoves to begin with)
As for me, I always carried a thermal lunch box (the Elephant brand).
Back in our day, quite a few people had thermal lunch boxes, too. haha