SMHI sometimes warns of a "cooling effect" - but what does that mean?

Often it's the wind that's behind it - but how much colder does it get when it's windy?

In Södertälje there is a test facility for trucks that can create basically any weather.

When SVT's Nils Holmqvist and Torbjörn Averås Skorup visited the facility, it was to experience a rugged winter climate.