You can see that a thermos flask will be a great companion for any outdoor activity! Using a Thermos Flask is Environmentally Friendly The Okadi is a 2.5L flask which offers extremely good capacity for both family and group adventures. It is fabricated from stainless steel which gives excellent core strength and durability. This thermos will last for a long period of time indeed. The 18-8 flask is from the renowned brand Stanley. Stanley has been serving people since 1913 and this model is truly legendary. No other brand apart from Thermos themselves can boast such heritage. Dimensions

As we said before, vacuum insulation is important for keeping the heat energy inside your flask, and the Hydro Flask does this well. It is made of stainless steel that is extremely good for heat retention. Since the American manufacturer, Thermos, came to fame, the term has become slang for vacuum-insulated flasks. Although the terms are largely interchangeable, the original scientific phrasing is 'vacuum flask'. A range of scientific research has shown that BPA can seep into food or beverages and potentially cause a range of issues for the brains of fetuses, infants and children. Additional research suggests a possible link between BPA and increased blood pressure. You may not have heard of ‘BPA’, but in a similar way to aluminium in camping kettles, it should be avoided when you’re looking for a thermos flask. BPA stands for Bisphenol A, and it’s a chemical which has been used to make certain plastics and resins since the 1960s, and was commonly found in thermos flasks.Button-operated lids are more efficient to use than twist-and-pour stoppers – we found the button-operated lids to be more secure than the twist-and-pour stoppers. The downside of this approach is that a high capacity flask will be big and bulky. There’s no getting away from it. However, if you’re able to split your gear equally between all members of the team (e.g. one walker carries lunch, another carries the picnic blanket etc) then overall you will use less space than if you each carried smaller flasks. Other useful design features to look for include a wide mouth, which makes for easier cleaning and filling (especially if you want to add ice cubes to your flask). In addition, many larger flasks incorporate ‘twist and pour’ spouts, so you can pour from the flask without having to completely remove the stopper. An integrated cup is also useful. Smaller flasks often feature lid designs that allow on-the-go swigging or one-handed operation. We hand-washed each flask with hot soapy water and let them air dry overnight, then ranked them on smell. You can leave your house with a full bottle of coffee on Friday evening and can have a nice walk with a cup of hot coffee on your weekend destination even on Saturday evening! You will definitely get a duration of 24 hours, and this model performs equally well for hot and cold temperature contents. In Use

We dropped each flask five times from 90cm to mimic a dropped flask. Those with large dents that inhibited function or ability were rated low. As we said before, the Milu is more bowl-shaped and can easily be eaten from directly. The 6.6cm wide opening is extremely convenient for easy filling and eating as well.This flask from OKADI gets full marks for its capacity and versatility. OKADI is a brand that has been serving people with quality products for the last 20 years and this particular model is their flagship model. It’s a big flask for big groups The Smardy flask is manufactured with high-quality stainless steel that makes it extremely durable and we are confident it will perform well over the long-term. It utilizes a silver coat in the vacuum portion of the flask which enhances heat retention. 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. The Thermos has dimensions of 31 x 8 x 8 cm and weighs only 515g – a great size for a day hike. A 1 litre capacity is about the optimum in our view – enough to comfortably serve two people with hot or cold drinks throughout the day without being too much of an impediment to carry. 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.

If you take your thermos flask to the local coffee shop and ask them to fill it up instead of having your drink served in a disposable coffee cup with plastic lid then you will be reducing the amount of landfill and waste material which gets produced from these establishments. Win win in our books! Why ‘Thermos’? 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 / This thermos flask is made of a combination of Stainless Steel, Polypropylene and Silicone, and the dimensions are an excellent 21.1 x 12 x 9.1 cm. It is sized extraordinarily well for solo hikers who are concerned about size and weight but still wish to carry a hot brew around to warm up with. In our opinion this is one of the best thermos flasks on the market today. Some thermos flasks are designed to be handily-sized for solo use on hikes and outdoor adventures. Others are larger for bigger groups or car and campervan travel. Choose wisely, or get a couple for different activities.

None of the flasks leaked from the main body – however, some flasks can't be filled to their stated capacity without liquid coming out when you screw on the lid. We’ve reviewed a selection of the best thermos flasks, ranging in size from 470ml to a whopping 64oz (1.8 litres). Bigger flasks usually retain heat better than smaller flasks, but are typically bulkier and heavier. We’ve compared their performance with our own temperature test. What Is The Best Thermos Flask? Flasks are more 'smell prone' than 'stain prone' – none of the flasks we tested had any staining after cleaning, but some retained a faint coffee smell. 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.

All materials on the Stanley are very robust and have a quality utilitarian feel to them. You can be assured that the food-grade stainless steel used on the Stanley won’t give a metallic taste to your drinks at all, but offers excellent heat retention. Heat Retention is a major factor determining the usefulness of a thermos flask. It directly affects how long your drinks or food will stay warm or cold.

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. Thermos flasks use an ingenious mechanism which consists of dual layers separated by a vacuum cavity between them. The vacuum is a region of space with no air or anything at all in it – this creates a natural barrier to heat leaving or entering the innermost chamber holding your drink. That’s why liquids in the flask remain hot or cold for longer than they would in a standard plastic bottle. Key attributes: Very light, design enables one-handed drinking, wide mouth for easy filling and cleaning. 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.