High and Low Temperature Thresholds can be changed when you you login to myspool, click on MY DEVICES, and then click on MySpool Temperature Sensor. You can then select your temperature units, Celsius or Fahrenheit, and set Low and High thresholds.  The thresholds set to -100 are ignored.  When your changes have been entered and you clicked Save, they are saved in the cloud for your sensor.  To make your sensor aware of these changes, unplug your device and plug it back in.  Otherwise those changes will be transmitted to your device when it checks in, usually once a day.