To battle heatwaves we need to drink plenty of water. In my experience cold water is much more effective. Then why not use our wits to create cool water. I’m suggesting a product that uses a simple peltier device powered by a solar panel that is then used to cool water for drinking. I’m not thinking of a portable refrigerator. I guess you can make it more effective by creating a contact area with the water and the peltier device.
Example image just to clearify the idea. Here maybe one should use two water containers. One that you cool and one water container you transfer heat to. Here the chilled water container is small compared to the heated container. Showing both ideas.