The temperature at which Nitrogen becomes a liquid is -196o C – very, very cold.
Watch this video to see what happens to these balloons when liquid nitrogen causes the air inside to cool very rapidly.
Source: MIT Physics Demo -- Balloons in Liquid Nitrogen, YouTube
Now watch the following video which explains how this phenomena relates to Charles' law.
Source: Gas volume and Kelvin Temperature, kosasihiskandarsjah, YouTube
This interactive application will also help you get an understanding of how volume increases with temperature increase.
Change the temperature by sliding the bar on the bottom, then watch what happens to the volume of the chamber of gas. Click on "Show Data Table" and then "Show Plot," to see a graph of the data.