“hyst” stands for hysteresis. In a sensor’s configuration, it’s the threshold below which the temperature must return for a sensor to no longer be considered critical. In your case, if the “edge” sensor reports a temperature of 94°C or above, it will be considered critical; once the sensor is critical, it will only become non-critical if it reports a temperature of -273.1°C or below (which can’t happen).
See the “Thermal Hysteresis Mechanism” section in the `sensors.conf` manpage for details:
> Many monitoring chips do not handle the high and critical temperature limits as simple limits. Instead, they have two values for each limit, one which triggers an alarm when the temperature rises and another one which clears the alarm when the temperature falls. The latter is typically a few degrees below the former. This mechanism is known as hysteresis.