Moonwalker - Adventures of a Midnight Mountaineer

IT was a walk of exceptional beauty and solitude, a walk of 36-plus kilometres through the lonely back country between Loch Ossian and Kinlochleven

It was also a walk in stifling conditions under a constant beating sun, a walk that finished as a struggle and a suspected bout of heat exhaustion, thankfully at the minor end of the scale.

I had followed all the rules for walking in high heat: packed plenty of fluids, wore protective eye and head gear and put on plenty of sunscreen, left route notification and took regular breaks in the shade. Despite all this, I still suffered.

There was no one reason for my troubles, rather a series of little problems and decision-making that all added up to highlight the dangers of strenuous walking in blistering temperatures.

The plan was multi-purpose, but centred on the ascent of Glas Bheinn, that Corbett outlier of the Mamores, on a long circuit starting from the shores of Loch Ossian. It involved dropping to Loch Treig, turning west by the waters of Abhainn Rath past a couple of bothies to the old house at Luibeilt, then up and over Glas Bheinn for a return via Loch Chiarain.

All fine on paper, but as is so often the case, the reality on the ground proved different. I had an 11-hour window, more than enough time for the task ahead. But it wasn't the distance so much as the terrain, the undulating nature of the tracks and paths meaning I was constantly losing minutes on each section and having to press harder.

It probably didn't help that I hadn't gone to bed until the wee small hours due to a walk up Leum Uilleim to catch the sunset the previous evening. Even the wildlife appeared to be in slow motion: a diagonal of ten geese flying lazily over Loch Treig should have raised a red flag that this was going to be a harder day than expected.

The path by the twisting waters of the Abhainn Rath was dried out and pocked with bleached white, exposed tree roots, hard underfoot until I reached the stepping stones for the Staoineag bothy. So far, I had been on schedule, but the ground softened for the next few kilometres to Meanach and I had a fair amount of to-ing and fro-ing to avoid the boggiest ground, accompanied by some severely irked golden plovers.

I was now running slightly behind, but took time out for a short rest in the cool of the bothy. It was hard to worry about the clock when the landscape was this captivating. I crossed the water to the infamous ruin at Luibeilt, its fearsome reputation neutralised by the brilliance of the day, then took the rough stony track heading towards the eastern side of the Mamores. I left it just before the drop to Loch Eilde Beag, taking to the open slopes of Glas Bheinn.

The ascent was a mere 500 metres, but at times it felt eternal. The pace slowed dramatically. There were plenty of rest stops on the constant uphill slog and I was running seriously low on fluid, rationing the remainder to a few precious sips. The streams that were supposed to occupy this grassy western face appeared to have gone on holiday. There was the consolation of a sensational view to the Grey Corries, although their pale profile matched exactly how I felt – dried out and leached of all moisture.

I dumped my pack on finally reaching the ridge to make the short push to the summit. The views all round – to the peaks of Glen Coe, the Nevis Range and the Mamores – would have brought a tear to the eye had I had any to spare. I was now nearly six hours in and that was when I realised the big error – there was no get-out clause, no short-cut return. The next target was the tiny Lochan Tom Ailean, a blue splash in the centre of a bog then more ascent to a teasing, mirage-like horizon. 

The seconds kept slipping, but once I had crested the ridge it was an easy drop to the bothy at Loch Chiarain. I had banked on replenishing my water supply here but any hope of instant refreshment was soon dashed – the river was virtually empty, the flow sluggish. I had to fill up from the loch, which meant purification tablets and another half-hour wait for a drink.

The next 7km to Loch Treig was a stop-start affair and the final 6km uphill to Corrour so slow it felt at times as though I were going backwards. I had to stop once to be sick, but managed to reach the station house just 15 minutes late for the club meal.

I needn't have bothered. The concern on the faces for the ghostly figure that stumbled through the door was obvious. I couldn't face any food. I barely made it to the bathroom where I was violently sick. I left the company and went back to the hostel for a shower, some proper rehydration and a lie down in the dark. An hour or so later, I was back to normal although food would have to wait for another day. It's likely I had a relatively mild case of heat exhaustion. 

It's important to know what to look out for. Symptoms can include feeling faint or dizzy, excessive sweating, clammy skin, muscle cramps, nausea or vomiting. Heatstroke is more serious and needs immediate medical attention.

Despite believing I was well prepared for such a long, hot day, my catalogue of minor miscalculations proved how it can all go wrong very quickly.

I shouldn't have tackled this length of walk so soon after the sunset walk, and I should have taken the ground conditions more into account.

I should paid more attention to the combined ascent rather than just that of the hill – it was a 500-metre climb to Glas Bheinn, but the day's total was more than double that amount.

I should have had an escape plan – it helps to build an early get-out into every walk.

I should have carried more even water, I shouldn't have relied on finding more along the way in such dry conditions.

And I shouldn't have given myself a deadline. A few hours' rest in one of the bothies and a walk out in the cool of the evening would have made more sense rather than rushing back while becoming increasingly exhausted.

Most of all, I should just have picked a less ambitious outing in such stifling conditions.