Yes, you can add any liquids, both hot and cold, in the Tumbler.
You can track different drink types of liquids (water, tea, coffee and Wave products) in the HidrateSpark app.
NOTE: The HidrateSpark PRO Tumbler and HidrateSpark PRO Bottle using the FLIP LID are the ONLY HidrateSpark products that can be used with HOT liquids.
Please DO NOT put HOT LIQUIDS in any other models.