There are people who talk about surviving in the wild. And then there is John Hudson.
Explorer and author Levison Wood puts it simply: "When it comes to survival and getting out of trouble, listen to this man. John is the real deal."
He is also, as it turns out, a man with firm and well-earned views on what to wear in the field.
As the British Military's Chief SERE Instructor - SERE standing for Survival, Evasion, Resistance and Extraction - John Hudson FRGS is the man responsible for teaching the most demanding skill set in the armed forces: how to stay alive when everything has gone wrong. His students aren't beginners on a weekend course. They're the instructors. The ones who will, in turn, teach others to endure the unendurable.
It's a role that takes John from frozen Arctic terrain to scorching desert wadis, from dense woodland to open ocean - wherever the military needs men and women to be prepared for the worst. Along the way he has authored the survival manual used by the armed forces of multiple NATO countries, appeared in front of millions as a resident expert on Discovery's Survive That, and written books translated into editions across Bulgaria, Hungary, Romania, China and North America.
The test that matters
When John spent several weeks in the Woolf PureFleece® QZip while training a new cohort of SERE instructors in Cornwall, it wasn't a product trial in any comfortable sense. The Cornish coast in late March through mid-April is a proving ground in its own right. Hard frosts in the mornings. Blazing sun by midday. And what John describes with the cheerful resignation of a man who has worked there a long time as "the inevitable sideways Cornish rain." Working in woodland - scrambling, demonstrating, moving hard then standing motionless while others learned - the demands on a mid-layer are unforgiving.
His verdict? "Fantastic."
Coming from the British Military's Chief Survival Instructor, that single word carries considerable weight. But John went further. The QZip, he said, gave him "a great thermal balance when static or working" - and across those weeks, it took "a fair bit of hammer" and stood up to all of it.
That phrase - thermal balance when static or working - is not throwaway language from a man like John Hudson. In survival training, the ability of a mid-layer to regulate body temperature across wildly different activity levels isn't a nice-to-have. It's the difference between hypothermia and not. When you stop moving in cold, wet air after sustained exertion, the fabric against your skin determines what happens next. Fantastic, in this context, is a serious word.
Why wool. Every time.
For John Hudson, the choice between natural merino wool and synthetic performance fabrics isn't a close call. It never has been.
“I always prefer wool to synthetics when I’m in the woods - or anywhere else to be fair - especially here in the UK. Because of the air trapped in its fibres wool retains great insulation properties even if it’s absorbed some moisture, and down here in the rain that’s a given”
This is a view rooted in experience rather than preference. Synthetic fleeces retain moisture against the skin, chill rapidly when wet, and - a detail that matters more than most people realise in the field - generate odour quickly in sustained use. Merino wool actively manages moisture, insulates even when damp, and stays fresher far longer. When you're deep in woodland for days at a stretch, in the kind of mixed conditions John routinely works in, these are not minor considerations.
The woods are hard on kit
One of the subtler tests of woodland work is what it does to fabrics over time. Branches, bark, equipment buckles, thorns - everything catches and pulls. John was direct about this: "Working in the woods can be quite hard on knitted tops." Many performance knits snag, pill and lose their integrity quickly under that kind of sustained contact.
The PureFleece® QZip didn't. Its close weave, John noted, "didn't snag at all" - across several weeks of exactly the kind of work that separates genuine field kit from kit that merely looks the part.
“Plus, wool is brilliant to wear around an old school campfire as stray sparks from crackling logs won’t burn holes into it, like they do almost instantly to anybody wearing smelly polyester."
"It has no vices that I could find," he concluded.
From the man whose entire professional life is built on identifying failure points before they become fatal ones, that is about as unambiguous an endorsement as it gets.
Too good for the job?
There is one thing that slightly bothered John about the Woolf PureFleece® QZip. It looked and felt too refined for what he was putting it through.
"My only negative is that it looks and feels far too sophisticated for my line of work!"
He's already solved the problem. The same QZip that navigated frost, sun and driven Cornish rain in the woods will also be going to the pub with jeans. Which is, in many ways, exactly the point of PureFleece® - performance without compromise, wherever life takes you.
John Hudson FRGS is the British Military's Chief SERE Instructor, a Fellow of the Royal Geographical Society, bestselling author and broadcaster. His books How to Survive are published internationally. Find out more at johnhudsonsurvival.com