One hour. That's all the sleep I achieved. Thousands of thoughts danced around my mind, most notably:

• Danny. The anxiety of not knowing how he is, and contemplating every possible outcome.

• Wind. It is so strong up here it sounds like a tornado is blowing through the camp. It repeatedly knocks over the condiments on the table inside the tent.

• Voices. I hear porters talking to each other at one point, their torches flashing past my tent. I presume it must be time to get up soon, but there's no wake-up call. I discover later that they had just returned from taking Danny down.

• My feet. They are frozen.

 

1 a.m. eventually arrives. I jump up and dress quickly: five layers on top, four on the legs. two pairs of thick socks, two  pairs of gloves, two beanies, a buff for the face, plus hand and feet warmers in my pockets and shoes. I look like an inflated snowman. Popcorn is provided as a pre-trek snack, and it disappears within seconds. I then sit impatiently, eager to start the hike to the summit.

 

As we head off, FC reports that Danny made it down to the next campsite, Millennium Camp, and his condition started to improve. He and the crew stayed there in a hut overnight. My relief is palpable.

 

The hike commences over large, uneven rocks, some with angles so close to perpendicular I don't know how my boots stick to them. I'm relieved when the volcanic gravel starts half an hour later, which carries me most of the way to the top. The gravel causes me to skid occasionally, but in general it's a fairly solid surface. I was expecting to find the type of loose scree where you take two steps forward and slide back one, but it didn't materialise. I have no idea where the path is, or how FC finds it by torchlight. It all looks the same to me.

 

FC regularly asks how I am feeling, enquires about the pace and begins conversations to check if I'm coherent. It's comforting to know that he is looking out for me. For once the pace is acceptable, and possibly even a tad too fast. I find I can't wear the buff over my face, as I need to suck in all the oxygen I can get. It sits around my neck and chin for most of the trek.

 

Not wearing a watch means I have no idea how long we've been walking, how much further it is until the top, or when the sun will start to rise. FC gives me occasional elevation updates, which are the only way I can mark my progress.

 

Patches of snow appear around 5200m, which is ironic as this is when I start peeling off layers. I'm surprised and relieved by how warm I'm feeling, but it's only 30 minutes later that the cold sets in. The layers go back on, the zips go back up. My lips dry out and my nose runs, and I'm fairly certain snot has frozen to the end of my nose, like icicles (or would that be snotcicles?). At least the snow is hard and compact, making it easy to walk on. We have to be vigilant to avoid any slick ice that has formed alongside the snow.

 

Halfway up we pass a group of four hikers and their crew. Apparently they arrived at our camp late last night, undertaking the six-day Machame trek. Their guides sing a rhythmic chant as they make their way up. I'm glad FC isn't doing the same.

 

At 5400m the water in the hose from my water bladder freezes. I have a bottle in my bag, but I can only access it when we stop for breaks (which, at my request, are few and far between). At one rest point, FC offers me ginger tea. The hot liquid is comforting, but as soon as I stand still for more than a minute the cold reaches all the way through to my bones. I tightly grasp the hand warmers in my pockets, providing a small comfort. The only effective remedy is to continue moving.

 

I battle between wanting to go faster to warm up, and having to put the brakes on to get enough oxygen in. I'm acutely aware of how laboured my breathing is becoming, so oxygen ends up winning this contest. My pace already feels extremely slow, but I end up slowing down even further. I think I would struggle to beat a sloth in a race right now. It's a complete U-turn from the rest of the week.

 

Slightly below 5500m, FC announces that we have hit the point of no return. He explains that if you make it this far, you will almost certainly make the top. I'm not sure if this is an actual point that all guides know about or just a theory that FC believes in, but it fills me with confidence.

 

Several times my thoughts wander to memories of overnight ultramarathons I have completed. This experience is similar in many regards: I can't see what's ahead of me, I'm exerting myself to a slightly uncomfortable degree, my breathing is heavy but manageable. Just like in ultras, I know that as long as I keep putting one foot in front of the other, I will make it.

 

Times flies, and before I know it the first hints of light are appearing on the horizon. Looking up I'm surprised to see we are close to Stella Point, a landmark that indicates we have reached the crater rim. Now the gravel has turned into a fine sand, where our footsteps kick up clouds of dust. As I stop to watch the streaks of colours forming across the sky, I realise I haven't eaten anything on the entire trek. I pull out an energy bar from my bag and discover it is frozen solid. I have to snap pieces off with my teeth and warm them up in my mouth before they become chewable.

 

Making it to Stella Point is a huge relief. The hard part is done, now it's just a gentle incline around the rim to Uhuru Peak, the official summit. I peer over the ridge and I'm astonished to find the crater full of snow. When I think about it, this shouldn't be that much of a shock, but climbing several volcanoes in the past and never seeing a snow-filled crater has skewed my expectations. Here is my first chance to pull out the camera and, even though the sun hasn't risen yet, I make up for the last five hours by taking hundreds of shots of basically the same view.