Key attributes: Leakproof, practical design enables one-handed drinking, wide mouth for easy filling and cleaning That being said, we found that performance was not quite as good as a dedicated drinks flask – the Milu will keep your hot drinks hot for six hours and the cold ones for 10 hours.

If you’re after a large flask, the Oneisall 2L is a great stainless steel option with a lovely ergonomic design. This is a high-quality two litre flask which is capable of serving drinks for the whole family – great to bring along for day trips in the car or campervan.Thermos should just rename their 1 litre ‘Light and Compact’ vacuum flask as “The Daddy” because it effortlessly delivers everything you would expect from the company who developed the vacuum flask as we know it today from Sir James Dewar’s original prototype in 1904. You can see that a thermos flask will be a great companion for any outdoor activity! Using a Thermos Flask is Environmentally Friendly The Oneisall measures 34.5 x 11.5 x 11.5 cm and weighs 1.2kg. For a large capacity flask, those are not actually bad specifications. And it really does look the business! Beautiful lines as they say! When single-use plastics started getting a bad rap, S’well became the drinks bottle of choice for a host of celebrities and ‘influencers’. But they’re not all style over substance – the design consists of a triple-walled construction incorporating a copper layer for improved insulation. This flask is lightweight and practical – the ergonomic shape makes it easy to hold, the really wide mouth makes for easy drinking, filling and cleaning, and the grooved lid makes it easy to open, even if screwed on tightly. It’s sure to draw admiring glances if you leave it on your desk at the office. It’s just a shame that the capacity is a bit small, and it’s relatively expensive for a little flask. Full Specifications This flask has a familiar design with a classic ‘pop’ stopper that makes for easy pouring. With cheap, inferior flasks these are often prone to leaking but with this Outwell version the component seems well-made and reliable. It certainly didn’t leak on test. It’s a simple, inexpensive flask that makes use of a classic tried and tested design. The wide mouth makes the flask easy to fill and clean, while the cup’s plastic liner ensures you won’t burn your mouth. On the other hand, it is fairly bulky for a 750ml flask, with a small cup compared to some other designs. The external finish is also a bit slippery and prone to scratching. Full Specifications

You should carefully consider the required capacity of your flask before buying one. Have a think about how many people will require a drink from it, and who will be the person carrying it around. Is it for home use (some people take a flask to their home office in the garden), or carrying on a walk for rest and recuperation? Nothing beats a hot brew when you’re tramping around the hills on a winter hike. It’s like we’re hard-wired to appreciate that soothing warmth spreading around our bodies like a “Ready Brek” glow. The original and, judging from the results of our temperature test, still the best. This stainless steel flask is very durable, with a silicone base to protect against dents. The two-part stopper closes securely yet pours easily and has an integrated cup. In terms of outright heat-holding performance for up to 8 hours, nothing can touch the Ultimate Series. It was the best-performing flask we tested overall. It is relatively lightweight too. And if you’re concerned that the 500ml capacity will be too small, it’s worth noting that Thermos also makes a larger 900ml version. Full Specifications Available in a range of colours (we like the electric blue), the flask is highly suitable for camping trips and general travelling refreshments. Pouring is very easy due to the superb flexible handle fabricated from silicone. Another advantage of stainless steel it that does not leave a metallic taste in the mouth or residual odours. However, it is always worth cleaning your flask thoroughly with hot soapy water between uses.

The temperature performance of the Smardy is quite praiseworthy. It gives around 12 hours for hot drinks and 24 hours for cold drinks. Certainly good enough for day trips in any conditions. Gave it it's first try out on a cold, wet trip up Ben Vorlich and was swearily disappointed to find that my coffee was cold after a couple of hours! At that point, I decided I'd had enough of 'buy cheap,buy twice', and bought one of these Stanley flasks. Capacity: 600ml (20.3oz) / Temperature test: 0 hrs 90°c, 90 mins 79.6°c, 4 hrs 66.5°c, 6 hrs 58.3°c, 8 hrs 51.6°c, 24 hrs 22.2°c / Stainless steel construction / Wide mouth opening / Capacity: 1 litre (33.8oz) / Temperature test: 0 hrs 90°c, 90 mins 86.5°c, 4 hrs 81.6°c, 6 hrs 78.1°c, 8 hrs 74.7°c, 24 hrs 53.7°c / Plastic-free stainless steel and silicone construction / 18/8 food-grade stainless steel interior doesn’t retain or impart flavours / Integrated double-wall construction cup / Twist and pour cap with 360° pour-through design / Internal Thread Design for increased thermal performance / Durable Klean Coat finish. BUY NOW: KLEANKANTEEN.CO.UK It has been utterly brilliant. It keeps my coffee roasting hot, even on a trip up Narnain and Ime on a snowy day when wind chill was (apparently) making it feel like -20c!