@gagraham, As of now there is no update available for Active 2 watch. However, I request you to contact our live chat support or SMS support as your gear watch is overheating and they would help you with further options to setup your device for service. So that the technician would examine the watch and check the root cause of the issue.
@vbovi, there is no option to delete bixby from the phone. However, you can re-map the bixby button to open any other apps on the phone. You can find this option in settings >> Advanced Features >> Bixby key.