When necessary it's standard practice with industrial HVAC to cool down the air until the moisture drops out for dehumidification and then heat it back up again to the required temperature. Presumably climate control and re-heat in cars mimics that process.
On my C55 AMG the book says ..with (hot) engine switched off but key turned if you push the button a red light will come on and the fan will blow low, hot water from the engine will circulate thereby warming the cars interior until the water cools down or the cars battery runs flat...or words to that effect. Not sure if its the same on a Vito. Try it on a cold day.