It's good to lock your doors to keep intruders out.
Sven is trying to sleep, but he's been cooking all day so his house is really warm.
Sven wants to cool his house down.
Sven closes all his windows and turns on the air conditioning.
Sven opens his front door and windows and lets the cool evening air come in.
A burglar passes by Sven's house when he sees that the front door and windows are shut tight.
A burglar enters Sven's house while he sleeps and takes his valuables.