I have never been so relieved to see a washing machine in my life. Three hours into our journey to Bosa, Sardinia, and I had already managed to spill an entire iced granita down my only pair of walking trousers. The hire car was sticky, my dignity was in tatters, and my partner was doing that silent laughing thing where she pretends to sympathise but is actually storing the moment for future dinner parties.

The drive from Alghero Airport had started so promisingly. Coastal roads, cork trees flashing past, the Mediterranean glinting through gaps in the hills like someone was teasing us with postcard views. We stopped at a little bar in Villanova Monteleone for what I confidently ordered as "a quick refreshment." What arrived was a lemon granita the size of a small bucket, which I then inverted spectacularly while attempting to point at a goat on a hillside. The goat, I am fairly certain, judged me.

By the time we reached the property, a traditional Bosa townhouse with terracotta roof tiles and shutters the colour of faded coral, I was wearing my emergency shorts and a expression of profound humility. The owner, a wiry chap called Franco who spoke English in abrupt bursts, took in my appearance with the practiced neutrality of someone who has seen worse. He showed us the roof terrace first, presumably to remind us why we had come. The view stopped my granita-related whinging instantly. The Temo River curled below like a lazy afterthought, and beyond it the old town climbed the hillside in a jumble of medieval pastels, all pinks and ochres and terracotta, as if someone had upended a box of watercolours and let them settle.

Franco explained that the weather was about to turn. "Tomorrow, very hot," he said, making a gesture like an oven opening. "After, maybe wind." He shrugged in that particularly Sardinian way that suggests meteorology is more philosophy than science. We had planned our entire week around coastal hiking, a series of ambitious walks we had mapped with the enthusiastic delusion of people who live in Manchester and think thirty degrees sounds pleasant.

The next morning proved Franco right. We set off early for the walk to Torre Argentina, a coastal tower ruin about four miles west, thinking we would beat the heat. By nine o'clock the limestone path was already radiating warmth like a storage heater. The maquis scrub smelled extraordinary, all wild rosemary and heat-sharpened thyme, but my emergency shorts were not designed for serious walking and I was developing what I can only describe as a personality conflict with my own thighs.

We made it to the tower, a crumbling sentinel on a headland where the sea smashed against rocks in explosions of white, and sat in what little shade its walls offered. My partner, who is sensible and Finnish and therefore treats sunshine with appropriate suspicion, produced water and a hat she had tried to make me pack. I had mocked the hat. I now coveted the hat. The walk back became a tactical retreat, punctuated by stops at any bush offering shadow, and a lengthy pause at a tiny cove where we paddled like children until our feet stopped throbbing.

That evening, on the roof terrace with a bottle of Vermentino and the sun dropping behind the hills, we recalibrated. Franco appeared with figs from his garden and confirmed the wind was coming. "Better for walking, maybe," he said, though his shrug suggested he was merely being polite. We spent the next two days exploring Bosa itself instead, wandering the cobbled streets of the Sa Costa quarter, finding shade in the cathedral, drinking espresso in squares where old men played cards with the intensity of chess grandmasters.

When the wind arrived, it came as a maestrale, that dry north-westerly that sweeps down from France and turns the coast wild and wonderful. We tackled the coastal path again, and it was transformed. The heat had broken into something energising, the sea had turned from lazy turquoise to proper Mediterranean blue, and we walked for hours without that desperate, granular exhaustion that had flattened us before. We reached coves we had abandoned on our first attempt, scrambled down to beaches where the only footprints were ours, and ate bread and pecorino on rocks like people in an advert.

I kept the stained walking trousers as a reminder, though Franco kindly ran them through his machine while we were out. Some lessons need physical evidence. The hat, I am pleased to report, now travels everywhere with me, and I approach all granitas with the respect they clearly demand.