Snow-capped Mount Kilimanjaro, in Tanzania, stands 5895 m (19 335 ft) high and is the highest mountain in Africa. The hike up the mountain, although considered arduous, is attempted by dozens of people each day. About one in four actually succeed. A few years ago, we set out to climb it, planning to get to the summit and down again in six days. We had pre-arranged an experienced guide and, rather than carrying tents, chose to stay in huts provided on the mountain. We hired some down-filled clothing and sleeping bags with the help of our guide — but, when offered crampons and ice axes for hire, we both laughed at the idea. “This is just a walk”, we joked, “not a real climb”.

The first two days of climbing were moderately hard and it became progressively colder. At one point, our guide spent some time talking intently to a colleague who was on the way down. He then explained that a group of hikers, two days ahead of us, had been climbing through a thunderstorm when a young American woman was struck by a bolt of lightning and killed instantly. She had literally “blown up”, with lightning bolts arcing down her body and out through her torso and limbs to the ground, leaving huge flesh wounds. This macabre event caused us some anxiety. Our guide thought she had been struck because she was wearing a red parka, believing that red objects “attract” lightning. We pondered whether there was some scientific rationale for red gear being more likely than other colours to attract lightning.

We eventually reached the first hut and stayed overnight. Next morning was initially cold but comfortable. But then we struck rain, a strong wind blew up, and the chill factor sent the thermometer plunging. It became so unbelievably cold that we had to put on every piece of cold weather gear we had. This was our first sense of just how cold it can be at high altitude.

As we sat on a rock to rest, one of us noticed a scrappy piece of red plastic on a bush and began to deride those nuisance climbers who “show a complete lack of respect for the beautiful mountain surroundings by leaving behind plastic rubbish to contaminate the pristine environment”. We then saw another piece of red plastic, then another, and soon realised that there were dozens of such pieces in a circle of about 10 m diameter. We then noticed a carefully constructed mound of rocks adorned with fresh flowers. It suddenly dawned on us that this must have been the spot where the young American woman had been blown apart by lightning. The rough rock memorial must have been constructed by her fellow climbers. We were both awestruck by the frightening power of lightning.

We continued climbing fairly easily, and had decided in advance to spend an extra day at Horombo hut (at about 4000 m) to help us acclimatise. It was hard to watch our fellow climbers leave without us — people we had met in the first few days and who would probably reach the summit before us. As events unfolded, our decision to spend that extra day at Horombo set us up for life-theatening situations near the summit.

On our fourth day, we reached the highest hut, Kibo, at 4700 m. The views were quite beautiful, with a pink sunset on neighbouring Mount Mawenzi and absolutely pristine clear skies. We had a small meal — no one has much appetite at altitude — and turned in for a few hours’ sleep before the final hike to the summit, with the aim of being there at dawn.

We set off for the summit at about 12.30 am. It was a moonless night, but at that altitude the sky was filled with millions of stars that appeared so close we felt we could pluck them from the sky. Amazingly, the starlight was sufficiently bright to illuminate Kilimanjaro and adjacent Mount Mawenzi. It was unforgettably spectacular.

We were climbing with our guide and a trainee guide on his first ascent. We felt fairly confident that this last section of the climb would not defeat us. We had both tried to get fit enough by running up and down 50 flights of hospital stairs three times a week, and had taken precautions to avoid altitude sickness — climbing slowly, drinking plenty of water, taking prophylactic acetazolamide, and taking the extra day to acclimatise. As we began, I was surprised to find that I was extremely breathless despite walking slowly. The snow was hard and, as we had not brought headlamps, we stumbled in the frozen boot marks of previous climbers. Recovering from each stumble required much energy and produced marked breathlessness. We found the climb extremely arduous, and experienced effort-induced nausea plus the bitter, penetrating cold. I felt certain that I would not make the summit. In lucid moments I cursed my oxygen-dissociation curve for its failure to “shift to the right” and be more generous in donating oxygen. The physical and mental struggle to reach Hans Meyer cave, a third of the way up to the summit push, was monumental.

I had seen published photos of Hans Meyer cave (named after the first man to climb Kilimanjaro) — which show it as virtually dry. But we found the cave totally ice encrusted, with large icicles hanging down from its roof. The temperature was −20°C to −30°C. We rested briefly at the cave, which allowed me to recover somewhat.

As we pushed on laboriously, we noticed the bright stars disappear and within a few minutes we were enveloped by cloud, strong winds, and then driving, icy snow. The blizzard made climbing treacherous and reduced visibility to almost zero. To our surprise, and alarm, virtually all of the other climbing groups had turned back. The only person who didn’t was obviously an experienced mountaineer, who rapidly passed us wearing crampons and swinging his ice axe rhythmically to cut steps in the snow. To see the other groups stop and then turn back made us a little concerned that we were taking a considerable risk in pushing on. Nonetheless, we were both determined to continue up the mountain. At this point, Mark, a cardiothoracic surgeon whose hands generally prove fairly useful in his profession, hadn’t been able to move or feel his fingers for some time and was convinced he had significant frostbite. This did not change his determination to continue the climb. He thought that, as he already probably had some frostbite, going on to the summit was unlikely to make it worse.

It is hard to describe how much emotional effort was required to keep climbing. Taking each step required every bit of mental endurance and concentration. It would not have been so bad if we had crampons, but we only had boots and so we slipped a lot. And every slip was exhausting. Everything in our lives — our families, our professions and all our previous life experiences — faded into a vague, dark background as our whole world was reduced to the small space between our ice-encrusted eyes and the snow slope in front of us.

Dawn began to break and we were able to see a little more clearly in the faint light through the billowing ice and snow. It was around this time that we had two frightening experiences. First, I lost my footing and began to slip backwards down the mountain. It crossed my mind, with surprisingly lucid mathematical precision, that my slide down the mountain may increase in velocity and end by my crashing at near terminal velocity into Kibo hut 915 m (3000 ft) below. However, I managed to roll over and, aiming for a large rock, slid feet first into it. This life-threatening event produced marked and unrelenting breathlessness. I recovered slowly, and we continued to struggle on up the steep slope towards the summit, kicking our boots as deeply into the snow as best we could to gain precarious footholds.

Then the second frightening event occurred. Mark slipped and began sliding down the mountain. He frantically grabbed at a rock protruding from the snow and this stopped his fall. He hugged the rock above his head with both hands, his body hanging down, and his feet flailing helplessly, unable to get any foothold. Every effort to kick a hole in the snow to try to gain a footing caused the snow to just fall away down the slope. I tried to help him, but couldn’t do much. The guide retreated down to our position, kicked a foot hole himself and then helped haul Mark above the rock. Mark lay prostrate in the snow, unable to catch his breath for 10 minutes or so. He later described this sensation as what it must feel like to die of respiratory failure!

The guide encouraged us to keep going if we wished, although he later confessed that on a number of occasions he had decided that neither of us could possibly make it to the summit. Doggedly, we pushed on. We reached the top at about 8.00 am. It was an anticlimax — we were unable to see much. Although the blizzard had eased off slightly we were still besieged by falling snow and mist. The only reason we realised we were at the summit was that there was a small sign welcoming us to the top of the mountain.

The video camera, laboriously carried to the summit, only worked for a few seconds in the cold, but that visual record of our achievement is very precious to us. We shook hands and joked with our guide. However, he was more interested in leaving the summit as quickly as possible, warning us that “the weather is going to get bad”. Mark remembers thinking at the time that this was a somewhat superfluous statement. It didn’t seem conceivable that it could get any worse!

We hiked, slid, crab walked, and glissaded down the steep slope through the whiteout. It didn’t look like the same route that we had come up on — it looked even steeper and we both felt that our guide was completely lost, and that at any moment we would glissade over the edge of one of the cliffs. We had read that 10 people die on Kilimanjaro each year, some by getting lost and falling over ice cliffs, and we thought that the same fate was destined to befall us. Eventually, we reached Hans Meyer cave and began to feel that we would safely descend the mountain.

What should have been a physically demanding, but easily manageable, hike turned out to be an unexpectedly dangerous adventure for us both. The disappointment at not being able to see the famous dawn view from the Kilimanjaro summit was minor compared with the sheer adventure of the experience, the knowledge that very few hikers made it to the summit that day, and the experience of two close friends struggling together against exhaustion, cold, fear, danger and disappointment. We were inexperienced mountaineers. But we were both able to help each other when we each faced danger, and we felt a very strong bond with each other. We felt an incredible sense of achievement because we had overcome all of the difficulties.

And we learnt some lessons:

• Get very fit by walking and running up stairs (not just on the flat) before undertaking a climb up Mount Kilimanjaro.

• Get professional advice on cold weather gear, especially modern thermal underwear, wind-resistant but “breathable” jackets, and good-quality down-filled gear. It can make the difference between being miserable or comfortable. (Many times as we climbed I said to myself that I would pay $10 000 to anyone who could have given me any of that gear, right there and then.)

• Take anti-altitude sickness precautions.

• Hire a reputable, experienced guide — inferior guides may not be primarily interested in getting you to the top — the earlier you turn back, the less work and less risk it is for them. And we did meet someone who could have died for lack of a good guide. As we descended through the storm, we found her stumbling along, severely hypothermic, disoriented and unable to speak. Her guide had let her set off up the mountain without gloves and other warm gear, and had not followed her into the storm.

• Hire crampons and an ice axe. We scoffed when we were offered crampons, but if we were doing the climb again we would undoubtedly hire these climbing aids, even though it is rare for Kilimanjaro climbers to strike a blizzard.

• Take digital cameras, including a video camera, with you, even though they are heavy and inconvenient to lug at such an altitude, and the exhaustion produced by climbing reduces one’s motivation to take photos. The resulting pictures are irreplaceable and worth every effort.

• A useful website is www.climbingkilimanjaro.com

But, in the end, the experiences and rewards we gained from our adventure were such that neither of us could possibly have anticipated how much it would enrich us as individuals and friends.