In reply to mypyrex: Bit of a side issue but BMC insurance costs went daft a couple of years ago so I started looking around to find that the free Travel Insurance which you got with Nationwide account (and I think other banks do similar) was almost as good as BMC and better than the basic BMC one. For £20 it is extended to Worldwide and covers trekking up to 5450m (you need another extension for mountaineering, climbing or above 5450m).
It will not cover existing or known conditions, I declared a family member and they then specifically excluded anything resulting from that specific condition of that person.
I always used to use BMC and still do for Expeditions, but not for general travel cover now.