Use your Phone as a Thermometer!
Now, you can use your Phone as a Thermometer!
This app works best on devices with a dedicated temperature sensor.
(Eg: Samsung Galaxy S4/Galaxy Note 3)
On such phones, the readouts you see should be an accurate representation of the temperature around you.
The app "should" still work on other phones (i.e. ones without a dedicated sensor) as well.
On such phones, the temperature displayed is that of the phone's internal electronics/battery.
Now, if your phone was on stand-by for a long time (say 1 - 2 hours) - the temperature of the device will be approx. the same as the temperature around you.
In other words, the temperature displayed "should" be pretty good representation of temperature around you.