My mom, when I would get sick, would make me drink lots of hot tea, or sometimes soup, believing that it helps.
Edit: As followup on comments: There is fair confusion on why am I asking about water and not specific beverages used, and there is reason for that - I am not looking for tea having caffeine or soup having nutrients that would help to recover kind of answer, but rather on beverage which is mainly water being hot, I recall being fed them as hot as possible, and once/if they would cool off being reheated/replaced by new ones. So focus really is on hotness not type of beverage or it's nutritional value.
Does drinking hot tea (or other hot drinks) help when you're sick?