A food flask with a hot meal inside is a great way to stay warm while stargazing.


A perfectly clear sky is every astronomer’s dream, but as there are no insulating clouds keeping in the day’s heat the best observing nights are often the coldest.

There’s nothing worse than having the perfect conditions for stargazing, only to be forced to call it a night early because you’ve gotten too cold.

Staying warm while stargazing is vitally important, and a hot meal of pasta or soup will not only warm you up from the inside, it’ll give your body the energy it needs to keep going throughout the whole night.

How does a thermos keep your food warm through the night?

Most thermos’ keep your food warm using a double layered flask with a vacuum in between.

Heat can’t conduct through a vacuum, and so it takes a lot longer for it radiate away its thermal energy and cool down.

These internal layers are frequently made from fragile materials such as glass, and so they often have a steel or plastic layer over the top for added protection.

The flasks then have an air tight lid that stops hot air from escaping and cooling down the food.

Many have a separate external lid that can be used as a bowl or cup.

Read on for our favourite food flasks available on the market today.

Thermos Stainless King food flask

With a huge 710ml capacity, this Thermos food flask can hold a big meal to keep you warm and energised throughout an entire night’s stargazing.

The broad opening gives you enough room to eat directly from the flask with a fork or spoon, or you can use the external lid as a bowl to portion yourself out a cup of hot soup.

The Thermos’s keeps your food to stay hot for up to nine hours, or cold for 14 hours (if you want to use it for your summer picnics as well as stargazing)

The flask is available in a range of striking metallic colours so you can match with your telescope or just pick your favourite colour.

Also available in a smaller 470ml version.

Good For You food flask

This food flask is great for using with thick gloves on, as it comes with a convenient carry handle and a non-slip base to help prevent you dropping it while trying to open it.

The handle is attached to external lid, giving you something to hold when using it as a bowl.

A built in foldable means you don’t have to worry about bringing cutlery with you.

Comes with a drawstring bag to protect the brightly coloured exterior.

If you find yourself at a loss for what to put in your flask, then they’ve got you covered there as well as the flask comes with a e-book of recipes.

It’s available in both 530ml and 730ml sizes, and has a 7cm wide opening. Stays hot for 9 hours and cold for 16.

Stanley legacy QuadVac food jar

  • Buy now from Stanley (based in the US).

Made from rust resistant stainless steel, the Stanley QuadVac food jar is built to last – it even comes with a lifetime warranty.

The outside has an easy-grip wrap that not only provides a comfortable handle to hold, also has a slot for the provided spork.

When it comes time to clean, the wrap can easily be removed, allowing you to run the main body through a dishwasher. Both internal and external lid are designed to be easy to wash.

Built Food Flask

With a practical and contemporary design, this flask has a silicone strip for easy grip (as well as helping to stop your hands getting cold on the outside).

If you prefer to just eat your dinner straight from the flask, there’s only a single lid with no separate bowl cutting down on the number of parts you have to unscrew and clean up.

Has a silicone strip running around the outside that will remain at a comfortable temperature to hold even if when the rest of metal exterior gets cold throughout the night.

Prime Horizon food flasks

This 500ml flask comes in an insulated carry bag. As well as helping to keep your dinner warm for longer, it also has an easy to attach carabiner so you can fix it to the outside of your bag.

Keeps food hot for 6 hours and warm for 24 hours and has a foldable spoon.

The inner lid not only seals the flask to prevent leaks, but also functions as a small food pot for snacks or seasoning.

Insulated tiffin box, Förskaffa

If you want a choice of options while your out and about, then the Förskaffa tiffin box comes with two separate tiers.

Each section acts as a 14cm diameter bowl, making for a much more comfortable eating experience.

There’s a carry handle on the lid, for easy transportation.

However, the tiers click together rather than being securely fastened, and the insulation only keeps food warm for three hours, meaning this would probably be best suited for when you want to keep a meal ready at your side while observing in your back garden.

Blockhütte insulated food flask

If you care about the environment then this flask was specifically created with sustainability in mind.

The flask is designed to be easy to clean, and prevent mold build up ensure it'll last a long time, while all the plastic elements are made with recycled material.

The outer lid works as a muge with a handle, while the inner lid has a special mechanism that lets air in and out to prevent the it from sticking (as the food cool, the hot air in the flask with also cool and contract, which can make thermal flasks difficult to open.

Comes with a sustainable coconut bristle cleaning brush you can use while out in the field, and is dishwasher safe for when you get home.

It's supplied with a cotton carry bag and a unique double ended utensil, with a fork on one end and a spoon on the other.

Available in 530ml and 730ml sizes.

Hydro flask insulated food jar

Keep your food at the perfect temperature with this food flask.

This is another food flask where there's no external lid to double up as a cup, so is best if you like to eat directly from the flask.

The sealing lid has a soft grip that easy to open even with gloves on (and also makes it easier to do up tightly to avoid leaks).

Available in 235ml and 355ml sizes for a snack, or larger 590ml and 830ml for a more sizable meal.


The main highlight of this flask’s sleek design, which is available in a variety of colours.


Elizabeth Pearson
Ezzy PearsonScience journalist

Ezzy Pearson is the Features Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.