There are few luxuries and accessories that dedicated hikers afford themselves, but an insulated flask is one of them.
Insulated flasks all work in the same way, using a vacuum double-wall design to create a thermal layer. But they vary in terms of size, efficiency, and weight.
For hiking, you want the lightest possible option. But bigger, bulkier models can keep liquids hotter or colder for much longer. We've curated our top-rated insulated drinks flasks to help you choose the right one for your next trek.
The best insulated drinks flasks
Best insulated flask

Description
An insulated flask should prioritise the job of insulating, in our opinion. Weight saving comes
Pros
- Several volumes available
- Very tough plastic parts
- Wide and narrow drinking
Cons
- Heavy
2. 360° Wide Mouth Insulated Bottle 750ml
Best Value
Description
This vacuum insulated bottle will keep drinks cool for 24 hours. Combined with its convenient sip
Pros
- Wide and narrow mouth options
- Magnetic attachment for cap
- Good value
Cons
- Other have better insulation
Best flask for day walks

Description
If all you need is something in which to carry a single serving of hot drink – be that a mug of
Pros
- Compact
- Stanley tough
- Leakproof mug
Cons
- Smaller volume than others here
Best for two

Description
When tea for two is on the cards, this is the perfect solution. Cleverly storing two cups in its
Pros
- Ideal for two people
- Includes two cups
- Not too heavy for its size
Cons
- Stanley Master Unbreakable Thermal Bottle has better insulation
5. Thermos The Revival Flask 500ml
Retro and effective
Description
Brimming with nostalgia – a Thermos just like your granny used to have – the retro Revival (also
Pros
- Memory lane looks
- Still durable
- Pretty good insulation
Cons
- Only one volume size
6. Camelbak Chute Mag Vacuum Insulated Stainless Steel Bottle 750ml
Best lightweight insulated flask
Description
Camelbak's Chut Mag bottles come in insulated and non-insulated varieties, many colours, and
Pros
- Relatively lightweight
- Clever magnetic top
- Many volumes and colours
Cons
- Others have better insulation performance
7. Hydro Flask Wine Bottle
Best for summit celebration
Description
This flask will keep your sauvignon blanc chilled or your mulled merlot hot for hours. It's
Pros
- Great for celebrating a tough hike
- Goes nicely with Hydroflask Wine Tumber
- Doesn't retain flavours of previous contents
Cons
- Hardly essential
Best for toughness

Description
A proper traditional beefy flask that, unlike traditional flasks, is almost unbreakable. Big and
Pros
- Excellent insulation
- Bulletproof
Cons
- Heavy and bulky
What to look for in an insulated flask
Volume: Do you need something to keep a takeaway latte warm, or do you want a day’s worth of cuppas in your pack? Is it just for you, or will you be sharing the contents? These factors, along with how much weight you’re prepared to carry, will decide the volume of liquid you need to fit in your flask.
Weight: Remember, one litre of water weighs one kilogram. A flask will only get heavier when full, so consider the empty weight of the flask and its volume to avoid overburdening yourself.
Drinking method: Some flasks come with a separate cup, while others are intended to be drunk from directly. The latter of these may have different openings, and some will be better suited to cold drinks than hot, lest you risk burning your lips.
Robustness: Most modern flasks are less breakable than the traditional glass insulated models, but some are better than others. If you tend to chuck your pack around with gay abandon, it’s worth making sure you choose a tough one.
Level of insulation: Good insulation comes at a price, both in terms of actual cost and weight. Cheaper, lighter flasks may keep the contents warm for a few hours. But if you want your last sip of the day to be as hot as the first, you may have to spend a little more and tolerate the extra grams.