I'm looking for a phone which will be immune to lots of sweat and rain. I don't do cases. I have been looking at waterproof phones such as the Xperia Z3. However, from Sony's website we see: "Never immerse your device in salt water, or let the micro USB port, headset jack, or other uncovered parts come into contact with salt water." This seems that the device is not meant to be sweat on, as sweat it full of salt. Are there any phones out there that are actually fine to use while sweating?