Hello. Welcome to Android Central.
I see the Nexus 5 has a barometer sensor, according to specs.
http://www.reddit.com/r/Nexus5/comments/1u8o51/barometer_use/
Mostly for internal monitoring according to above.
I re-downloaded Antutu yesterday and it said I have all the sensors except a temperature sensor.
My service menu says I do, and it's working fine.
(ADDED - I have a Samsung Note 3)
The GSam app will show the battery / charging temperature.
There are a plethora of crazy add on devices for smartphones, so I'm sure there are probes out there as well.