How about cold food for summertime!

I sometimes send vegetable soup, rice/pasta dishes (with veggies and meat) or dumplings. In addition to thoroughly heating the food, I also pour boiling water in the thermos a few times to make sure it's hot when the food goes in. If you have a good thermos you should be fine. Maybe try testing it at home first to make sure things are still sufficiently hot come lunchtime?

First PP here. I've sent in soup for my son in a thermos. I tried mac and cheese once and he didn't like the change in consistency after a few hours in the thermos. I've also sent in pasta w/ marinara. He was fine with that. I haven't tried anything else.

OP here. PPs, so there is no way to send hot/warm lunch when no microwave available? Please tell me if there is a safe way to do hot lunch. TIA.

Sounds dangerous to me. "Warm" is the perfect environment for bacteria to grow.

I would stick with cold stuff.

Depends on the food.

I have a toddler and would like to send warm lunch in an insulated container. We cook the night before and set the leftovers in the fridge. The daycare does not warm food. Can I heat it in the morning (6 am) and send it in Thermos? Is the food safe if I cook the night before, refrigerate all night, warm in the morning and stick it in thermos for 5/6 hrs? Thanks.