I’m holding the cup to my face.

Anywhere else, this might look a little strange; but this is Orkney, and it’s an autumn morning with the promise of winter felt in every exposed extremity.

I’m bone-marrow chilled, and my legs, shoulders and jaw have a convulsive life of their own. Around the cafe, people are peeling off layers in the steamy warmth, colour-coded into garish (tourists) and muted (locals), and everyone has a mug in his hand. I’m keeping hold of mine by squeezing it in my palms, scalding life back into my deadened fingers. They cramp when I curl them around the handle, like I’ve just completed a handwritten exam.

Outside, a half-hearted gauze of rain is turning into a drizzle. It’s a morning that affirms Kirkwall’s architectural emphasis on clean-lined durability – unembellished concrete walls and glistening slate roofs, stone and more stone. The streets through the town centre are a thousand shades of grey, but somehow the result looks far from drab. As in Stromness, on the eastern side of Mainland, it feels like the residents understand how to nurture their heat and light: little of either leaches out into the streets, and at night, you’d be forgiven for assuming Orkney homes must be as chill as the average Scottish castle.

I’ve got a warm scone in front of me, on a clean plate covered in fine scratches. The jam actually tastes of strawberries: I don’t know if it’s the jam or my tastebuds at work. I’m becoming aware that the last twelve hours simultaneously rank among the most bizarrely foolish and the most enlivening of my whole life. And that this cup of tea is the best I’ve ever had.

The constituency of Orkney shears off the northeast tip of Scotland in a scatter of windblown islands, and true to its appearance, visiting Orkney requires a certain stoicism. The maritime climate blunts the lower extremes of temperature found inland, so frost is rare even in winter – yet the weather is notoriously fickle.

On the afternoon ferry from the northern island of Westray, I incautiously predict it will be a fine evening. I’d sat by the bay of Pierowall all morning, baking in an intense hush I’ve only ever found on Westray, listening to distant boats slap and gurgle on the water like a mouth worrying a boiled sweet. My third stay in Orkney, and my first without being part of a University of York archeological excavation. Each year’s season of work covered July through August, when meteorological emphasis shifted from (windy) sun-kissed summer to (windy) rain-lashed autumn. Now it’s firmly into the rainy season, so I should know better – but the sky is clear. The air is a little brisk, of course – in Orkney, the wind very rarely lets up, and gales (winds greater than 60 kilometres an hour) can occur at any time of year.

But conditions look promising. This is important. My connection for the ferry to Scotland is at nine tomorrow morning in Kirkwall, outside the magnificent rose-sandstone cathedral of St. Magnus. But I have nowhere to stay in Kirkwall overnight: the hotels, guesthouses and youth hostel are fully booked. So I’ve decided to stay awake.

And why not? I’m perfectly warm, swaddled in layers of fleece, shod in padded walking boots. My rucksack contains everything essential for a week of exploring Orkney. I have a working mobile phone, for emergencies. And I’ll be spending the first few hours in the Ayre Hotel, filling myself with rump steak. The air’s cooler than expected as I disembark onto the pier – but it’s nothing to worry about, so I don’t.

The air I encounter, as I later step out of the Ayre onto the now-glistening street, is damp and cold enough to make me splutter. Mist hangs over the sea, only truly substantial at a distance and visible as a thin spray of droplets diffusing the glow of the streetlights. A haar, or North Sea fog.

It hisses against my face as I walk, coating my glasses and giving me 70’s-disco vision. I’m heading southwest, past the impressive remnants of the 12th century Bishop’s Palace, and out of town. Eleven hours still to kill, so I decide to see where the road goes (I know it skirts the airport and curls up into Deerness, but they’re just words on a map). There’s a long, calf-stretching hill – and suddenly, looking back, I’m afforded an eerie view of Kirkwall with the streetlights reduced to fuzzy glows, the rooftops festooned with cobwebs of mist. I ineffectually wipe my glasses with saturated glove-fingers, and head away from the light.

There’s a peculiar joy that comes with exploring your physical limits, and an hour out of Kirkwall I’m feeling warmed, supple and deeply content. To my left is the just-perceptible inkiness of Shapinsay Sound, occasionally prickling with boat lights as the haar eddies and shifts, and beyond it, the uninhabited island of Copinsay is marked by the dimmed wink of its automated lighthouse. Very occasionally I have to scramble onto the high verge as a car passes (heard far sooner than seen), but mostly, I’m walking comfortably on tarmac.

I can also see surprisingly well. The darkness in Orkney can be at once profound and unthreatening, as noted by Kathleen Jamie in Findings (and reproduced in The Guardian here)- and it’s the former quality that might cause problems were it not for a diffuse glow from the mist, as if it’s slowly sweating out all the light it has consumed. I pass roadside houses less and less frequently. It feels remote; less untouched than abandoned in a hurry, with the lights left on.

I walk for another hour, and lose track of exactly where on the road I am. Squinting at my map (lit by the light of my mobile phone) is no help at all. An insistent, irrational voice in my mind tells me that I should turn back – but I’m only an hour and a half out, with thrice that time remaining to use up.

I’d hoped to return to town by six, giving myself time to explore the centre and suburbs. But I’m getting gritty-eyed now, stumbly and sluggish.

Picking a suitably distant spot from the most recently-passed farmhouse, I check the fields. If I can find one sufficiently weed-strewn (hence in fallow, so I’m not damaging any crops), I can maybe huddle in a corner and grab a little sleep. I find a wire-fenced field, make sure there are no cars around, clamber over, and cumbersomely hop-stride my way through the waist-high, sodden undergrowth, away from the road. I also keep my head lower than the dry-stoned wall to my right, beyond which is the farmhouse that presumably belongs to the owner of the land I’m trespassing on. There’s a patch of walling that’s less jagged-faced than the rest so, sitting on my backpack, I get comfortable against it.

It’s 4 a.m. when I wake. The mist is gone – because it’s raining. Water has wormed its way through the gap between my hat and waterproofs. I’ve woken because I’m shivering so much, my head is juddering against the stones behind it. All the warmth I’d gained from walking is now spent. At first, I can barely lift my backpack, and I have to lean against the wall for support. It’s frightening to feel so weak from the cold. I need to move.

So, within minutes, I’m heading back to town, forcing a steady pace from myself, concentrating on breathing fast enough to push the chill out of my bones.

Just as any place is rendered strange by the cover of night, earliest morning can add an unnatural tinge, a hint of the artificial. Kirkwall at six a.m. is covered with a Hitchcockian quantity of birds, particularly raucous gulls cheeky enough to claim sole ownership of the road and plunge deep into litter bins for rubbish. Clouds of sparrows and starlings flick from one telephone cable to another, keeping their distance and squabbling for vantage points. A few locals eye me curiously as they head towards their early shifts. I’m sitting on a public bench outside the cathedral – I’ve mostly stopped shivering, but my arms and legs feel bruised by the violence of my body’s recent attempts to get warm.

Yet – I’m clear-headed. Energy reserves severely depleted, certainly, but aware of having enjoyed the last 12 hours, the strangeness of it all. (I also feel rather eccentric.)

A few hours later I’m in the cafe, breathing in the warmth, feeling the hot tea go down, the tingle of sensation returning to my feet. I feel exactly here, right then, and nowhere else.

How often are we truly, overwhelmingly aware of the present? The state of feeling comfortable comes from contrast, from the recent addition or subtraction of an experience. Perpetual comfort is invisible, intangible. It files the edge off your senses. And to sharpen them again, you can’t be afraid of discomfort, of the unexpectedly challenging. Sometimes you need to stand in the rain.

Walk into the dark.

Breathe in the cold.