My parents' house has a pretty old air circulation system, resulting in drastic differences in temperature throughout the house. In certain situations, they tend to stay in the finished basement for a sustained period of time. This device would monitor the temperature in the basement, and if it reached below a threshold, based on month (or perhaps even external temperature), it would alert the user to adjust the house thermostat. I hope to have it call the house (perhaps IFFT - https://community.particle.io/t/internet-call-button/17119/4), as that is their preferred message of communication, but I will require additional research
Parts
Particle Microcontroller
Particle Cloud Account
Thermal Sensor
1 1k Resistor
Wires