Competetive systems like those supporting Philips, GE all have at least one temperature sensor.
Why Wemo can't add one to its line card?
Imagine opportunities to create Rules based on defined also in rule temperature threshold which would trigger one or multiple Wemo Makers which could control HVAC at my house, lights or other Wemo smart outlers running local windows air conditioner in my garage if needed. With that I could also replace my main HVAC thermostat with two Wemo makers, one for switching between heatig and cooling and another to turn HVAC on and off. There would be so much more potential for Wemo Maker when I can sense temperature in one or multiple locations around the house.