Carry a plastic water bottle with you. Lots of uses. Any other uses you can think of?

Aside from the obvious of drinking water.

Put it close to your body for warmth or coldness. Can help regulate temperature off your bed.

I'm talking the plastic one use bottles. Rip the labels off to decrease its weight. If you're walking to a place that has water that you can fill up at, jetson all the water you have and fill up there if weight is a concern.

More cushiony then nothing.

Increases buoyancy for swimming.

Bottle deposit money.

If your boss sucks and you need to pee (shout out to home boy Jeff Bezos)

I've done all of these besides peeing.