Altitude Sickness - an introduction

I've never suffered with altitude sickness before. I thought it was a condition that befell only the unfit, the unprepared and the unaware. I was wrong. Having been back in Colorado for an entire week since the trip to England, and having trained hard during that week, I didn't consider the possibility of acclimitisation being a problem. I agreed to go for a backcountry tour to the Indian Peaks, in the west of Boulder county, without worrying that I was in any way unsafe to be in the hills.

Christa, John Schoofs, Bryan and I got a leisurely start from Boulder under cold but very clear skies. We drove to the east entrance of the Moffat Tunnel, outside of Rollinsville. The 14 mile long tunnel is a rail route connecting the Winter Park Valley with Boulder county. It starts at about 9000 feet and is the perfect spot to park and hit the hills. Colorado mountains are so gradual in their rise from the plains that you need a high starting point in order to find fun skiing. The east portal gives you just a couple of miles of flat terrain before everything kicks skywards.We set off after minimal faffing and skinned the direct route into the Arapahoe Lakes drainage. The open faces above always look so tempting, but with successive storms dumping unstable snow onto the hills, the choices for what was actually skiable were limited. I let Bryan and John do the decision making on avalanche danger - I've spent plenty of my life in the mountains, but very little of it in winter, and even less in places where a 10 foot detour could lead to huge consequences.We played it reasonably safe on the first run, finding fresh turns on mild slopes just a handful of feet away from our skin track. We spied an untracked bowl just a little bit above though, and that became the target for round two. It put us at 11,600 feet up (that's 3500 metres above Crackalands Farm). Even at the top of the chute, looking down over the bowl, I felt no ill effects of altitude. We took a cautious approach to the slope, stopping to see what was up with the layer of wind blown snow sitting on the powder. After Bryan made a smooth attempt, we all skied down, leaving fresh tracks and grins on the mountain.We started off on the way back to the car, with a little bit of powder to play with, but also a lot of skinning through the trees, and a little bit of uphill too. This is were I realised something wasn't quite right. Dizziness, sickness and a strong desire to lie down washed over me. I thought I'd eaten something weird, and it wasn't til Bryan mentioned altitude that it even clicked. I felt completely trapped in hypoxia. We skied down another 1000 feet, where I chose to take 5 minutes lying in the snow, then powered on through back to the car. As soon as we started getting lower, it felt like a pressure was lifting off my head, and I could actually ski/see straight. By the time we were at the car and I had a trusty cup of tea in my hand, I was feeling great. Other than sleeping like a baby for the next couple of days, I didn't have any lasting effects. I'm not sure what I could have done to prevent it, especially as Christa had been on the same travel plan as me, and not been affected whatsoever. Either way, I know what it feels like now, and I'll give my parents and Brother a little acclimitisation time when they come to visit next time!