Can I connect a relay to Freezer Warning Light Contacts

My new vestfrost chest freezer is in garage 60ft from bungalow, I know Vestfrost circuit shows a buzzer connected to same connections as Warning Light (but option missed off mine), I want to wire a DPDT Relay with 240vac Coil to Warning Light Connections to trigger a pair of alarm contacts on a wireless pager system so siren goes off in bungalow if temperature rises to warning light level. second set of contacts to trigger a 12v 180ma alarm type strobe on front of garage with battery power. If freezer fails I will have 2 reliable warning devices, I also have an emergency light wired with freezer plug to show if power down it lights up a panel in garage front (I am going to change this for another strobe). Due to illness I am in bed for a week at a time and I would have pager in house and see 2 strobes from my window to warn me of fault & get it checked out.
Is it safe to do this or could it overload the Warning/Signal circuit in thermostat.
I would rather have a warning device that sticks on back of freezer with a probe on wire that drops in freezer (like digital thermometer does) but instead of a buzzer & LED just an LED & a pair of NC Alarm Contacts that would open on a temperature rise, but can't find my dream. Help greatly appreciated.