Born in a bloody barn

I swear this one flatmate of mine was born in a barn. She keeps leaving both the inner and outer doors open. This evening , she's out sweeping the drive, and she's been out there for 5 minutes, with both doors open while it's 3°C outside. My room is now very cold, even though I closed my bedroom door as soon as I noticed it getting cold. Thankfully, she's moving out in a couple days. It seems pointless to even confront her with it, with her leaving so soon, but it's still quite irritating.