Two devices: Sensor and Interface. When interface device is close to sensor device and button is pressed, interface device produces electromagnetic field, to power up sensor device. Sensor device reads the temperature of the sensor and transmits reading to interface device using NFC technology.
Yes, you can implement sensor as a dynamic NFC tag and interface as an NFC reader device.
Take a look at following chips:
- Tag: STMicroelectronics M24SR
- Reader: STMicroelectronics CR95HF
P.S.: to power up a sensor you may consider energy harvesting chip such as ST’s M24LR16E-R