When it comes to feet, mine run cold and Im always searching for the perfect solution to keeping my toes comfortable when the temperatures drop to single or minus figures. So it was either very brave or very foolish for Northwave to take up the challenge with their Celsius Arctic GTX shoes. Warning: theres a lot of acronyms and product names in this review, such is the current fashion in the bike industry. Still, Celsius Arctic GTX does on the face of it sound impressively warm doesnt it? Luckily the period of riding in these coincided with the UK weather reverting to normal with a named storm, torrential rain, floods that then turned into a cold snap of windscreen scraping mornings and crunchy puddles, so all in all perfect test conditions!Northwave Celsius Arctic GTX the clean unworn editionOk, lets get some of the jargon and acronyms out of the way first, the Northwave Celsius Arctic GTX boots are advertised as having a Cirrus XT 4L membrane made by Gore-Tex for waterproofness and breathability, 200g recycled Primaloft Gold thermal padding inside and a 4 layer Arctic insole. More of a shoe with a neoprene cuff than a boot they close using a X-Dial SLW3 (think Boa but with a quick release lever) and a zip up the inside of the cuff. The sole has an aggressive looking Jaws Evo sole tread, with a SPD cleat pocket and the provision of fitting football boot studs at the toe for added traction if you are fit/mad enough to run with your bike on a cyclocross race.Enough of the jargon, what are they like to wear? Well i asked for a size larger than my normal summer shoe size as I intended to run thicker or waterproof socks with them and Northwave agreed that was a good idea. With a thicker sock on my feet I attempted to put them on for the first time. Theres definately a knack to it. Inside the shoe are two red straps to aid pulling them on and they are needed. It was a bit of a wrestle to be honest and i was instantly worried I needed an even bigger size. However once on and my socks straightened by wiggling my feet in the shoe they felt totally the right size and i had plenty of toe wiggle room. Infact they are sort of T.A.R.D.I.S like as they seem bigger when on than when putting on if that makes sense?Northwave Celsius Arctic GTX pull on strapsNorthwave Celsius Arctic GTX primaloft interiorOnce on and the dial turned to snug the front of the shoe down and the zip done up they feel really comfortable, theres loads of adjustment with the X-Dial and the neoprene like cuff fits well around the ankle and allows unhindered ankle joint articulation. So no resistance to pedalling.Northwave Celsius Arctic GTX sole & cleat pocketNorthwave Celsius Arctic GTX generous cleat adjustmentthe sole has a very generous amount of cleat adjustment, Id go as far as saying the most Ive experienced on any clip in shoe. I set it as far back as it could go thinking the shoes were like most others and soon realised I had to move the cleat back towards the toe which is unheard of in my experience! The sole is aggressive and theres lots of grip even without the toe studs for hike a bike sections. The close spaced knobs will get clogged with clay and leaves (your soil conditions may be different) but a quick bang on the pedals soon clears them though. Taking of walking, the sole has just the right amount of flex for trotting up muddy trails and lets face it more importantly they wont make you look like a penguin when walking up to the counter in your favourite coffee/cake/chip shop/pub. Despite this flex there is plenty of stiffness at the cleat for efficient pedalling.Northwave Celsius Arctic GTX test conditionsAre they waterproof then? the shoe part of the boot definately is, i know this because I deliberately on your behalf pedalled my bike through all the floods, stood in X-dial deep puddles and tried to (unsuccessfully) leap across a ford. The neoprene cuff though isnt, its weather proof but will eventually get damp from spray. Bear in mind though that theres a big hole in the shoe where your foot goes in so a wet sock cuff is equally caused by water running down the leg of my waterproof trousers as much as the neoprene. The good thing about neoprene though and why its excellent as a wet suit is that despite being damp it still insulates the wearer by trapping body heat. On the wettest day when i removed the shoes the top of my sock was damp but from the ankle down was as dry as when I put them on. Northwave Celsius Arctic GTX in the wildNorthwave Celsius Arctic GTX full frontalDespite having to really tug to get the shoes on the straps have remained intact. the X-Dial looks fragile put I have accidentally smashed it into a concrete bollard (Northwave sell spares) and the release lever allows very easy adjustment, in a juxtposition to putting them on the shoes come off at the end of a ride very easily which messes with my mind somewhat. Northwave Celsius Arctic GTX X-Dial adjusterNorthwave Celsius Arctic GTX side zipDid the Northwave Celcius Arctic GTX shoes keep my feet warm? Northwave neednt have worried (I expect they werent losing any sleep) as my feet stayed warmer in these shoes a lot longer than Ive experienced before. id go as far as saying they are the warmest cycling shoes/boots that Ive tried so far and as the temperature drops the further we get into winter im looking forward to spending longer out on the bike than previous years.Northwave Celsius Arctic GTX making wavesNorthwave Celsius Arctic GTX will never be this clean againThe Northwave Celsius Arctic GTX shoe is a comfortable, efficient pedalling, warm and weatherproof shoe thatll help you go further for longer in the grimmest of conditions.you can see more details on the shoes on the Northwave websiteNorthwave havent paid for this review, they took the risk of an honest review, there are no affiliate links or discount codes. I do (I hope) get to keep the shoes, not that anyone would want then after my plates of meat have been in them for a few weeks!