Clear Liquid?

Due to the heat (31C/88F) and humidity (feels like 40C/104F) here in Southe Ontario we are constantly being reminded to "Stay hydrated, drink plenty of clear liquids". This disqualifies fruit juices, colas, beer and many other liquids.

I'm not a fan of the local tap water, so my question is: Gin over crushed ice or vodka from the freezer?