There is more to homeless people than being homeless.
In many stores across the country Gatorade is on sale. Grab some, leave them in your freezer over night, and then tomorrow hand them out to the homeless you meet during the day. You have no idea how much that will be appreciated.
I frequently carry water for just this purpose. Thanks for the Gatorade idea. I can't do this all of the time but what I can do, I will.