How to handle low temperatures using Arduino Uno? I want to create a simple electronic temperature sensor using the Arduino Uno.

The environments I want it to handle is inside a fridge and near a heater.

Although I am sure the Arduino can easily handle a heater; my issue is that the Arduino may not be able to handle a fridge. 

A fridge also has the added problem of causing water vapor (and we all know water + electronics is never a good idea).

So my question is:


How would I create a temperature sensor using my Arduino Uno, that I can put in my fridge?
Are there any other problems I have not considered and how do I solve them?
Will I need a special type of casing? If so, which type?
Is an Arduino Uno even the best tool for this task?
Your Arduino does not have to be in the fridge, just the sensor. You can always choose waterproof sensor like this one to use with the arduino. Then you can always store your arduino outside the fridge. Same goes for the heater. Try to keep the arduino at room temperatures to avoid decreasing its life unnecessarily. 

As for an actual answer to the temperature ranges, here is a good answer