Icebreaker products are absolutely brilliant and having previously owned a lot of outdoor gear, e.g. Northface, Mountain Hardwear I started to look at alternatives. I now own multiple Icebreaker products and have worn them for hiking in the UK, aborad in hot and humid temperatures and also to hike Kilimanjaro. The best thing is the wicking so items don't smell even if you sweat, they are warm in winter and cool in summer. Socks can be worn multiple times (sounds disgusting but true) and this makes it great for outdoors. I also own some of the underwear from Icebreaker which is so comfy.
Prices are expensive but you can guarantee that items will last so it's a worthwhile investment. Delivery is prompt and their customer service has been great when I had some socks 11 months into a 12 month warranty were going thin (all clothing is guaranteed a year). I can't recommend these products enough.