Container to keep food hot?

I am also interested in knowing I have only ever used the Thermos brand as well and I had the same experience with not being warm at lunch time.

Hydroflask could be worth trying. I have an older version from years back vs their newer versions. I don’t recall testing heat for more than say 2 hrs though for the food containers. I’m a fan of their bottles and cups though for keeping ice overnight and hot coffee for a long time so I’d have to assume the food ones are legit!

Honestly, I use my Yeti coffee traveler with the snap label. It will keep food warm/hot for hours.

My kids took hot food in the Thermos Funtainer to school and their food was still hot. I know you mentioned you didn't have luck with Thermos brand, but maybe you had one that was a dud? Ours lasted for a couple of years without problem.

We've had good success with a classic Stanley Thermos for warm school lunches.

I second Kara B's rec for a Hydro Flask! I recently found one on super sale at Nordstrom's Rack too.
Also, have to second Lindsey's YETI rec. They make one with a lid that screws on too.

This Thermos was a bulletproof option for many years of school lunches. It doesn't leak, can be eaten out of with a spoon (wide mouth), and keeps food plenty warm. Pro tip: before putting the food in, boil some water and let it sit in the Thermos for a minute or two to warm it up.

smile.amazon.com/gp/product...

EDIT: It looks like Thermos has redesigned their food jars, so I can't speak to whether the current ones are as good as this model.

I really like DaCool's insulated lunch containers, like this one.

This Lunchbots thermos is great for soup or pasta and is piping hot when my kids open it four hours after I packed it. Now my kids love to ask me for “hot lunch” instead of a sandwich. I also like the other stainless steel, dishwasher safe and reusable (environmentally friendly) other containers from Lunchbots!