Negative temperature value in automation

How can I use negative value in my automation (it´s in celsius)?:
A want to trigger when temperature is warmer then -15C.
I´ve tried:

type: temperature
platform: device
device_id: ea1f626a066304800ddbf14aff7e55e4
entity_id: sensor.temperature_17
domain: sensor
below: -15
(above: -15)

platform: numeric_state
entity_id: sensor.humidity_16
attribute: unit_of_measurement
below: '-15'
(above: '-15')

It triggers on both below and above in both cases.
I´m having a temp sensor in my freezer and want to be notified when temp is warmer than -15C.

Thanks in advance.

trigger:
  platform: numeric_state
  entity_id: sensor.temperature_17
  above: '-15'