Drass is supposedly the “Second Coldest Inhabited Place in the World”. Do take that with a pinch of salt. Traditionally Drass was known as Hembabs with the word "Hem" meaning the same as it does in "Him" of the Himalayas. Basically a place which gets a lot of snow as this area got the most snow in the whole region.
Zanskar : The Valley of Copper
Zanskar has an area exceeding 7000 sq km and a population estimated to be between 18000 to 20000. It is located bang in the middle of the Great Himalayas which separate it from Kishtwar and Lahaul in the South. In the East it touches Tibet almost and in the North is Ladakh and to the East is what used to be Baltistan but now better known as the Kargil area. Zanskar gets its name from the Tibetan word for Copper "Zang" and Valley. So probably it was because of the Copper deposits it was called so. And the name stuck.