Another rubbish day on the weather front (strong headwinds all day, loads of spindrift, a lot of cloud) though the sun stayed around this time and we had a clear view of the mountains all day, which lifted what otherwise would have been a pretty miserable day. We'd aimed to do nine hours but the going was so slow and the surface so poor for the first three hours that we called it a day after eight and a half.

We left a depot yesterday, and both had a wash and a change of thermal underwear (before leaving our dirty clothes with the depot to collect on our return) which was a bit of a treat. We each have one more clean set -a long-sleeved top, leggings and boxer shorts - to last us until we get home, so we'll change again in a month or so! The bath consisted of taking it in turns to use the porch of the tent to strip off, have a scrub with some snow and/or antiseptic gel and put the now clothes on.

I prescribed myself a course of antibiotics last night as my stomach still wasn't right, and I'm already feeling far better (yay science and medicine!) I was thinking a bit today about remarkable it is that Tarka and I, essentially two very slow-walking pouches of warm blood, can exist out here for months at a time in the coldest of cold places, with only the equipment and food we're pulling along with us.

I went for an emergency, er, bathroom break as Tarka made breakfast this morning, and wearing only my boots, my thermals and a fleece the windchill felt truly malevolent, like it was stripping my body's warmth away with every passing second and wouldn't stop until I was the same temperature as the millions of acres of snow and ice that surround us. Yet with a few different bits of clothing, we can trundle along all day in some form of relative comfort, and at least without any digits falling off.

I think I've said this on a previous expedition, but out here I'm acutely conscious of my own heat, and of having to shepherd and protect it against nature. I often think of us as two tiny pinpricks of thermal red in a giant expanse of deep-cold blue, inching our way across its surface. The feeling of self-reliance and self-sufficiency is strangely satisfying, yet of course compared to Scott, Shackleton, Amundsen et al, we're soft.

There's no risk of scurvy and we're constantly swaddled by an electronic safety blanket. Right now, in the corner pocket of our tent, I can see the reassuring LED blink of our always-on satellite tracker, and there are ski-equipped aeroplanes that can reach us if we need help. I can't begin to imagine what it must have felt like to travel here a century ago. Clothed in canvas and wool, sleeping in reindeer skin bags, they may as well have been on the surface of Pluto.