The Great Thermos Debate

One of the questions I am asked most often is about how to send hot food with children to school. Most of you won’t like my answer – because there simply aren’t really any great hot food vessels on the market. Some of the big names Thermos’ on the market include:

  • S’Well Eats
  • Hydroflask Insulated Food Flask
  • Yumbox Zuppa
  • Thermos Foogo
  • Thermos Funtainer
  • Zojirushi Food Jar
  • Yeti Thermos
  • Klean Kanteen
  • Skip Hop
  • And the much discussed, Omie Box Bento Box

The questions I am asked most often include – what are the easiest to open thermos’ for kids, what thermos’ keep food the hottest. and are there any flatter thermos’ for things like pizza?

Which ones are “easy” for small kids to open? None. Heat retention is due in part to super tight fitting seals and screw lids. If children could open them willy nilly, they’d spill hot food on themselves, and that would be a liability for the manufacturer. For this reason, most children cannot open them solo.

What thermos’ keep food the hottest? Honestly – not many. All thermos’ require you to “charge” them, aka preheat them with boiling water for at least 5 mins prior to putting your food in to warm the thermos. However, this is rarely enough to keep your food out of the “danger zone” of bacteria growth. According to every healthy authority, food hits the danger zone between 4 °C and 60 °C. Most thermos’ CANNOT sustain that high of a temperature in the length of time between packing lunch and eating lunch in a day. Lukewarm food is almost certainly spoiled and should NOT be eaten unless you can confirm it hasn’t dropped below 60 °C.

Are there any flat thermos’ for pizza or foods that kids don’t want to mix around? No. No there isn’t.

Lots of people ask me about the Omie Box Bento Box too – it is marketed with a thermos bowl inside a bento box so cold food and hot food can go together. My opinion? It is TERRIBLE. Even with preheating or “charging” the thermal bowl, the hot food is lukewarm at best by lunch time. The cold food also heats up, and it’s all within the food safety danger zone. A bacteria breeding ground – bad news. Food safety requires food to stay at a specific temperature. This can be achieved for chilled foods with ice packs – but not for hot foods without a microwave (most schools have removed microwaves due to covid-19). The Omie Box Bento Box is also a super heavy box (3 to 4 pounds when willed with food) and is priced high at approximately $65-$70 CDN.

The advice I have to give – teach your kids, as EARLY as possible, to eat chilled foods or open any vessel you need to send their heated food to school in. Teachers cannot (and SHOULD NOT) be touching and opening 30 different lunches. This means bento boxes, lunch kits, thermos’, water bottles, and packaged food like fruit cups, yogurt tubes, cheese strings ( all of which exist in a teacher’s personal version of HELL). Teach them to open it all themselves – if they can’t open it, don’t send it. If they won’t consider eating cold food, they have to learn to open a thermos properly. (*this applies to neurotypical children – I recognize and empathize with the vast array of feeding difficulties that arise in neurodivergent children and I ALWAYS advocate for a parent to do the best they can with what they can*)

See? I told you this wouldn’t be a super fun conversation. A thermos for kids comes with a ton of challenges – if it’s easy to open, a kid could burn themselves and no manufacturer wants that liability. But most other thermos’ don’t keep food hot enough to ensure bacteria isn’t growing. Do people risk it? Sure. I just won’t sit in front of everyone and advocate for their usage (unless you can confirm the hot food vessel you use never dips below 60 °C before consumption. If you’re going to just send macaroni & cheese, or pasta with butter and parm, it’s “probably find” and you can buy whatever since they all kinda suck the same. Skip Hop ones are cute and go on sale often. Thermos FOOGO can be bought at Superstore. Amazon has tons.

I am definitely not the food police – but if you wouldn’t eat chicken nuggets out in a stainless steel container on a hot summer’s day and eat them after 4 hours – why would you send them in a thermos that won’t even stay as hot? Did you know most gastro symptoms in school aged kids are due to improperly stored/stored food? It’s food poisoning! Here are some helpful links:





Teach your kids to eat chilled food. Start now, even if your baby is only 9 months old. Start as soon as possible, and don’t get them accustomed to hot soups and pastas (or peanut butter and jelly sandwiches) because you’re in for a world of hurt when grade school starts.

2 thoughts on “The Great Thermos Debate

  1. I am new to your IG and really enjoying your humour and insights!
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