Best insulated flasks for hiking in 2025 | Tested and reviewed

An insulated flask should prioritise the job of insulating, in our opinion. Weight saving comes second. Consequently, the slightly beefy YETI Rambler isn't very dainty but is very good at keeping its contents hot or cold and is very well made. YETI doesn't state insulation times but we found the 1065ml kept tea hot for a full day and it could do so for longer.

The stainless steel body is great but what really impressed us was how solid the plastic screw top and spout were.

The YETI Rambler comes in many colours and five different volumes. We've used the 1065ml/36oz version, which is really good if you have the ability to carry and store it. The smaller 760ml/26oz is a good alternative otherwise.

This vacuum insulated bottle will keep drinks cool for 24 hours. Combined with its convenient sip cap (although it also has a wide mouth opening for filling and cleaning), it's ideal for cold drinks on the hill.

If all you need is something in which to carry a single serving of hot or cold drink – be that a mug of tea, a takeaway Americano, or a post-hike beer – the All Around Tumbler is perfect.

You'll need to keep it upright because it isn't leakproof but other than that it's a great insulated mug. It comes in a range of colours and two volumes.

When tea for two is on the cards, this is the perfect solution. Cleverly storing two cups in its lid and with a leakproof easy-pour stopper, the Thermavac will keep its contents hot or cold for over a day and makes sharing an on-the-hill cuppa simple.

The Contigo flask is the ideal travel flask because of two key features: it's lightweight and leakproof. We found the lockable the button operated lid very effective and also liked the optional tea infuser. But do note this doesn't keep drinks hot or cold for as long as some of the other flasks here.

Brimming with nostalgia – a Thermos just like your granny used to have – the retro Revival (also available in green and blue tartan) is also a highly practical flask for one. It features a removable mug, a flip-up pourer in its internal stopper, and excellent insulation figures.

Camelbak's Chut Mag bottles come in insulated and non-insulated varieties, many colours, and several volumes. They therefore offer the best range. The insulated stainless steel versions are also impressively lightweight.

You'll no doubt be intrigued by the magnetic cap. It's basically a clever way of keeping the lid out of the way while you're using the bottle.

This flask will keep your sauvignon blanc chilled or your mulled merlot hot for hours. It's designed specifically to swallow the contents of a whole wine bottle, but it works equally well for non-alcoholic tipples. We do of course say that if you're taking alcohol on your trek, be sensible and drink responsibly.

A proper traditional beefy flask that, unlike traditional flasks, is almost unbreakable. Big and heavy it may be, but if you need to keep tea on hand for the troops (or your walking buddies) this 1.9-litre bottle will keep its contents hot or cold for up to almost two days.