You could have it hot or cold I guess, I had a cold one and didn't like it but then I have never been a fan of Vanilla anything. Try a hot one now and cold next time and see what one is suitable for you, also don't forget if you like sweet coffee you can use sweeteners.
be careful of lumps, when i first did this i would shake it first in my shaker with a little water then add the hot water etc. But it didnt matter to me i didnt like it hot or warm and can only drink my shakes really cold with ice.