One or more additional sensors that do not measure {TAIL ~ hydration level} of the user can be coupled to a hydration sensing {HEAD ~ element} to determine the amount of fluid consumption for the user in different conditions 
One or more additional sensors that do not measure { TAIL ~ hydration level } of the user can be coupled to a hydration sensing { HEAD ~ element } to determine the amount of fluid consumption for the user in different conditions
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH