Quite the late reply because I don't check this account very often 🤣 the bag is protected from the sun but still it warms up through my body, the hose to my mouth piece has an insulation hose around it, so it doesn't get very hot / cold.
We have water tap points scattered through the country everywhere so active people can get free water, it's really great but you have to check google maps where they are and really search for it and in the winter they're closed.