Thermal Underwear

You will probably spend 80% or more of the trip wearing your thermals, including wandering round in the cabins in them, so make sure they are comfy. If wearing the same base layer for several days on the trot doesn't sound like you then make sure you have a second set. I didn't bother, and everyone is in the same boat - or on the same sledge!

Probably the best thermal underwear you can get is made by stormbreaker, a New Zealand company who uuse merino wool to make their products. Helly Hansen have been a popular thermals manufacturer, and they no longer suffer from the traditional nick-name "smelly helly"! There are many manufacturers out there advertising their super new fabrics, but so long as you avoid cotton, which soaks up sweat rather than wicking it away from the body, you should be fine.