The newly released Apple Watch runs by transmitting info to one’s smartphone, which is 1) now encouraged to be even closer to the body (contrary to international precautionary guidance) and 2) the phone is effectively a hotspot.  (It is most likely using BlueTooth to transmit the signal to the watch.)

https://www.youtube.com/watch?t=147&v=rwv-3wZocK4

https://www.youtube.com/watch?v=a6CUWKWpFAs

They retail for $349-$649 with higher end models costing $1,000 to $17,000.