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The best Thermos flasks for hot drinks on the go

Whether you’re commuting to the office or heading out on a hike, a thermos flask is perfect for popping in your bag so you can have a hot drink along the way. Take a look at the best thermos flasks you can buy, as recommended by Mumsnetters.

By Madeline Littlejohns | Last updated Dec 5, 2022

The best Thermos flasks 2022

With the cold weather arriving and the cost of living crisis taking hold, we’re all looking for things we can do to keep warm without spending too much money. A thermos flask is a great thing to help you do both these things.

If you’re at home during the day then you can fill a big thermos with hot water and use that for your tea and coffee throughout the day, instead of boiling the kettle each time you want a hot drink. And if you’re out and about at the office or the park with the kids, then taking a hot drink from home out with you in a thermos will save you from splashing out on a coffee to warm you up. 

Whether you want a big flask to last you a day of working from home, a travel mug for trips to the park, or a thermos to keep your tea hot on a hike, we’ve scoured the Mumsnet forums to find the best thermos flasks that mums have tried, tested and highly recommended.

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Here are the best thermos flasks to buy in 2022.

1. Best overall Thermos flask: Stanley Classic Legendary Bottle

Stanley Classic flask

Price on writing: £40.99 | Buy now from Amazon

Key specs

Size: 9.19 x 30.81 cm | Capacity: 1 litre | Colours available: Green

Reasons to buy

  • Amazing heat retention
  • Leakproof
  • Incredibly durable

Reasons to avoid

  • Only available in one colour

What Mumsnet users say

“I don't think you can beat Stanley's for this sort of thing. Way better than Thermos in my opinion.” (Recommended by Mumsnet user RaspberryThief)

Our verdict

Stanley’s motto is ‘built to last’ and it’s something they’ve stood by since 1913 when they first started making flasks that are rugged, reliable, and built to last a lifetime. This classic Stanley flask will hold a litre of liquid and will keep its contents hot for up to 24 hours, which is just incredible. It’s made with BPA-free stainless steel and is incredibly durable, withstanding speeding bullets, 4000 foot drops, and category five hurricanes during product tests.  

Mumsnet users love how well these hard wearing Stanley flasks work to keep their coffee hot and how they can be trusted not to leak in your bag. The fact that every part of the flask can be washed in the dishwasher is a real bonus too. 

2. Best Budget Thermos: Habitat Stainless Steel Flask

Habitat Stainless Steel Flask

Price on writing: £7 | Buy now from Argos

Key specs

Size: 6.7 x 25.5 cm | Capacity: 500 ml | Colours available: Silver

Reasons to buy

  • Great value
  • Lightweight
  • Leakproof

Reasons to avoid

  • Smaller capacity

Our verdict

This lightweight 500ml flask is the perfect size for popping in your bag without weighing you down. It looks great with its brushed stainless steel finish and will stand up to knocks and bumps. The flask has a twist and pour stopper and the lid doubles as a cup so you can have a cuppa on the go.

Reviewers who’ve tried and tested the flask say that it keeps their drinks lovely and hot for hours and that it’s the perfect size for a couple of coffees. The one thing to watch out for is water getting trapped in the rim of the lid after washing, so make sure you dry it off properly before using it again. 

3. Best large capacity Thermos: Thermos King flask

Thermos King flask

Price on writing: £24 | Buy now from Amazon

Key specs

Size: 10.5 x 31 cm | Capacity: 1.2 litre | Colours available: Cranberry Red, Copper, Duck Egg, Gun Metal, Matt Black, Midnight Blue, Raspberry

Reasons to buy

  • Large capacity
  • Excellent heat retention
  • Trusted brand

Reasons to avoid

  • Noisy

What Mumsnet users say

“Thermos food king has been the best we've had. Not the cheapest but so far it has been pretty indestructible.” (Vetted by Mumsnetter LunchWithAGruffalo)

Our verdict

Thermos has a reputation for being one of the best brands out there for thermal flasks, and this 1.2 litre King flask lives up to that reputation. Its big capacity is perfect for taking out on a hike or for filling up in the morning to use throughout the day at home instead of boiling the kettle multiple times. The vacuum insulation technology keeps drinks hot for 24 hours while the outside of the flask stays cool to the touch.

Mumsnetters love how reliable this flask is and how long it keeps their drinks hot for through the day. The one downside that users have reported is that the handle is quite noisy. It's designed to be moveable so it can tuck in neatly to the flask when you’re not using it, but the metal pieces clink a lot as a result when you move the flask. Not a deal breaker but it is something to keep in mind. 

4. Best Thermos for meals: Thermos King Flask With Spoon

Thermos King Flask With Spoon

Price on writing: £20 | Buy now from Amazon

Key specs

Size: 9.4 x 14.2 cm | Capacity: 470 ml | Colours available: Midnight Blue, Copper, Cranberry Red, Duck Egg, Gun Metal, Matt Black, Metallic Blue, Raspberry

Reasons to buy

  • Keeps food hot for up to nine hours
  • Lid doubles as a bowl
  • Folding spoon fits in lid

Reasons to avoid

  • Lid sometimes hard to open

What Mumsnet users say

“My three children have these thermos ones, they've had them for four years now and they still leave food nice and hot for lunch time. The lids are easy to unscrew and the little foldable spoon still going strong (and somehow miraculously not lost)” (Loved by Mumsnet user AdditionalCharacter

Our verdict

If you’re trying to save money by not buying lunch every day at work, then this Thermos King food flask is perfect for taking hot pasta or soups to the office with you instead. It holds 470ml which reviewers say is perfect for fitting in a whole standard size tin of soup and it keeps its contents hot for up to nine hours. 

We love the fact that this food flask comes with a foldable metal spoon that fits into the lid, and the lid itself can be used as a bowl. Mumsnet users who’ve tried and tested these flasks say that they’re really hardwearing, last for years, and are easy for kids to use for school lunches. A few people have reported that the lid can be hard to remove at times when the hot contents create a vacuum, but the overwhelming majority love this flask.

5. Best leak-proof Thermos for on the go: Contigo Travel Mug

Contigo Transit Autoseal Travel Mug

Price on writing: £27.07 | Buy now from Amazon

Key specs

Size: 7.5 x 21.5 cm | Capacity: 470 ml | Colours available: Biscay Bay, Matte Black

Reasons to buy

  • Leak and spill proof
  • Easy to use and clean
  • Lightweight

Reasons to avoid

  • Doesn’t fit in most cup holders

What Mumsnet users say

“Contigo all the way. Leak proof and keeps drinks hot hot hot.” (Vetted by Mumsnet user CrapAtThis)

Our verdict

The Contigo travel mug is perfect for hot drinks on the go, whether you’re pushing the pram in the park or taking the train to the office. It’s been specifically designed for one-handed drinking and is completely leak proof and spill proof. When the lid is twisted shut the autoseal technology means that nothing will leak out, and when you’re ready to drink just twist the top and press the button to take a sip.

Mumsnetters recommend this travel mug because it keeps drinks nice and hot and doesn’t leak at all if they carry it in their handbag. They also say the cups are sturdy and well made and still work perfectly after months of daily use.

6. Best Thermos for hiking: Klean Kanteen Classic Bottle

Klean Kanteen Bottle

Price on writing: £33.44 | Buy now from Klean Kanteen

Key specs

Size: 7.3 x 28.2 cm | Capacity: 592 ml | Colours available: Brushed Stainless Steel

Reasons to buy

  • Extra wide opening
  • Good heat retention

Reasons to avoid

  • Hand wash only

What Mumsnet users say

“For me, nothing beats Klean Kanteen for drinks. They don't spill and they keep the drinks hot for many many hours.” (Tried and tested by Mumsnet user user1471523870

Our verdict

If you want a classic flask to take hiking, whether it’s for icy cold water or hot tea, then you can’t go wrong with this one from Klean Kanteen. Its simple design will fit neatly into a backpack and you can trust that it won’t leak at all. The double wall vacuum insulation keeps hot drinks hot for up to 20 hours, and cold drinks cold for up to 50 hours.

The extra wide mouth of the flask means it’s really easy to add ice cubes to your drink to make it super cold in hot weather. Reviewers love the classic style of this flask and the fact that it really works to keep drinks hot or cold for long hikes.

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7. Best Thermos for coffee: Contigo West Loop Travel Mug

Contigo West Loop Autoseal Travel Mug

Price on writing: £21 | Buy now from Amazon

Key specs

Size: 9 x 20.5 cm | Capacity: 470 ml | Colours available: Biscay Bay, Dark Blum, Earl Grey, Gunmetal, Iced Aqua, Latte, Matte Black, Millennial Pink, Monaco, Raspberry, Red, Stainless Steel, Tangerine

Reasons to buy

  • Great range of colours
  • Leak proof
  • Durable

Reasons to avoid

  • Lid can be hard to clean

What Mumsnet users say

“Contigo west loop travel mug is my recommendation. My husband is in the car much of the day and has two of these. His drink stays warm all day.” (Recommended by Mumsnet user Greenshinyspoon)

Our verdict

The Contigo West Loop mug is perfect for your daily coffee on the go, whether you brew it up at home before you head out or pop into the local coffee shop along the way. The 470ml capacity is more than enough for your caffeine hit and the thermalock double-wall vacuum insulation will keep your drink hot for hours. The Contigo West Loop uses the same autoseal technology as their other travel mugs, so you just need to press the button to drink and when you release it the mug is completely sealed and leakproof again.

We love the look of these travel mugs and with the huge range of colours available you’re bound to find one to suit your style. Mumsnet users who own them love that they keep their drinks perfectly hot for a long time and that you can put them in your bag and know they won’t leak everywhere. The only issue is that the lid can be hard to get completely clean under the seal, but most users love the fact that it pops open and can be put in the dishwasher (the main body of the flask is hand wash only).

8. Best stainless steel thermos: Chilly’s Series 2 Bottle

Chillys series 2 bottle

Price on writing: £30 | Buy now from Amazon

Key specs

Size: 7.5 x 22 cm | Capacity: 500 ml | Colours available: Abyss Black, Arctic White, Blush Pink, Frost Blue, Granite Grey, Lichen Green, Maple Red, Peach Orange, Pine Green, Plum Red, Pollen Yellow, Whale Blue

Reasons to buy

  • Great choice of colours
  • Leak proof
  • Comfortable to hold and use

Reasons to avoid

  • Texture might not be for everyone

What Mumsnet users say

“Get a chilly's bottle. Honestly hot for at least 12 hours.” (Tried and tested by Mumsnet user Yodaisawally)

Our verdict

We love these bottles from Chilly’s that have a stainless steel core which is 100% food safe and rust resistant but are available in a range of great colours instead of being plain silver. The bottles are available in 350ml, 500ml, and 1000ml sizes so there’s one for every situation. They keep drinks hot for up to 12 hours and cold for up to 24 hours and the double wall insulation means they stay dry and cool to the touch.

The Chilly’s bottles are textured on the outside which gives them a bit of grip in your hand, although some users have commented that they don’t like the feel of it and would prefer a smoother texture. What everyone seems to love though is the way these bottles keep drinks hot for ages and the fact that they have a silicone ring on the base that makes them almost silent when you place them down on a hard surface. 

9. Best smart thermos: Flintronic Travel Mug

Flintronic Travel Mug

Price on writing: £14.99 | Buy now from Amazon

Key specs

Size: 6.5 x 23 cm | Capacity: 500 ml | Colours available: Black, Blue, Red, Pink

Reasons to buy

  • LED temperature display
  • Sleek design
  • Great heat retention

Reasons to avoid

  • Hand wash only

Our verdict

Fancy something a bit more high tech? Then take a look at this travel mug from Flintronic. It has an LED display on the lid that tells you the temperature of your drink, so you never have to risk burning your mouth by trying to sip your coffee when it’s too hot. 

We love the sleek design of this bottle and the fact that you can fit it in all standard cup holders. It will keep drinks hot for hours so it’s perfect for days out and in fact lots of the reviews on this bottle are from parents who use it for keeping water hot for making up their baby’s formula on the go or during the night.

10. Most stylish thermos: Hydro Flask

Hydra flask

Price on writing: £28.99 | Buy now from Amazon

Key specs

Size: 7.3 x 22.1 cm | Capacity: 621 ml | Colours available: Cobalt, Alpine, Carnation, Fog, Pineapple, Eggplant, Bayou, Black, Geyser, Pacific, Wave, White

Reasons to buy

  • Looks great
  • Durable and leak proof
  • Easy to clean

Reasons to avoid

  • Sports cap sold separately

Our verdict

For a thermos flask that looks great and keeps drinks hot for hours you can’t go wrong with a Hydro flask. The shape and design is sleek and classic but the range of colours keeps it fun. It also works brilliantly, keeping drinks hot for up to 12 hours and cold for up to 24 hours. 

The brushed metal finish means this flask is super comfortable to hold and reviewers love how well it keeps drinks hot when they take it out with them. If you’re using it for tea or coffee then the open mouth is perfect for drinking straight from the bottle or pouring into a cup. But if you want to use this for cold drinks on the go then you can buy a separate sports cap that fits perfectly and is still leak proof.

How to choose the best thermos flask for you

When you’re looking at thermos flasks there are a few things you need to ask yourself and think about to make sure you buy the best one for your needs.

First of all you need to know what you’ll be using the flask for.

Do you want a big one that you can fill up in the morning to last you all day or something smaller for having a single coffee while you’re out and about? Or do you want something that you can use for taking soup to work for lunch one day and a hot cup of coffee the next?

Knowing what you’ll use the flask for will help you decide on the size to go for and whether to look for a flask with an open top or a spout to drink from.

Next you need to know how long the flask will keep the contents hot. If you just want to take a hot drink with you on a walk then you only need it to stay hot for a few hours, but if you want to take a big flask of tea to last you the day at work then you need it to keep things hot for much longer.

It’s also worth making sure that the flask you buy has multi wall insulation which will mean that the contents stay nice and hot but the outside of the flask is still cool to the touch.

How do thermos flasks work?

A thermos flask is really two flasks, one inside the other with a gap between them. When they’re made the air is removed from this gap to create a vacuum which works as a layer of insulation to keep hot drinks hot and cold drinks cold.

How long does a thermos flask keep things hot?

It does depend on how well made the flask is, but most thermos flasks will keep things hot for up to 12 hours.

One thing you can do to help things stay hotter for longer is to preheat your flask by filling it with boiling water for ten minutes and then tipping this out and adding your coffee or tea for the day.

How do you clean a thermos flask?

Some flasks can be put in the dishwasher for super easy cleaning, but a lot of them are hand wash only so check the label before you do anything.

It’s best not to fully submerge a thermos flask in water because doing this could allow some water to get inside the insulation layers and stop it working as well.

Adding some water and washing up liquid to the flask and then giving it a gentle scrub with a bottle brush is the best way to keep your thermos nice and clean. Don’t use anything too abrasive on it to make sure you don’t scratch the surface.

What’s the best thermos flask to buy?

We highly recommend the Stanley Classic flask and Mumsnet users agree that it’s the best thermos flask you can buy.

These flasks keep drinks hot or cold for an incredibly long time so they’re perfect for filling up in the morning to keep you going all day long. They’re also really hard wearing, dishwasher safe, and completely leak proof.

How we chose our recommendations 

We’ve thoroughly researched the best thermos flasks you can buy this year, including tried and tested experiences from a wide range of reliable, trusted sources. Here’s how we carefully chose our top picks.

Recommendations from real Mumsnet users

Because we know that you can always trust a real recommendation from a real parent, we first headed to the Mumsnet forums to find out which thermos flasks Mumsnet users had bought for their own families. We compiled a list of the flasks they recommended for being good value and reliable.

Expert opinions

We then did some research across the wider web, looking at which thermos flasks had won accolades or been featured in ‘best buy’ lists across websites and print media. 

Authentic customer reviews

Finally we visited a mix of retailer sites and read the reviews there, to find out what real people thought of the different options.

Having collated all that information, we picked the thermos flasks we thought would make the best buys in several categories.

Why you should trust us

We work hard to provide unbiased, independent advice you can trust. We do sometimes earn revenue through affiliate (click-to-buy) links in our articles. This helps us fund more helpful articles like this one.