Ahhhh... outside. These crazy warm temperatures lately have meant that I've been able to spend quite a bit more time outside or with the windows open and I tell ya... my body is kind of loving it.
In the house in which I lived in the states before moving to Germany, there was always a ceiling fan on in every room (even the rooms that were not being used) and it drove me crazy. It seemed like a useless waste of electricity, and still may be, but coming to Europe and not having a fan in every room really made me notice how stagnant the air can get.
What started out as a quest to freshen the inside of my house turned into hours of research on the benefits of fresh air... and there are many! Fresh air can improve your blood pressure, strengthen your immune system and can even make you happier (oxygen increases serotonin, which in turn, can boost your sense of positivity). Additionally, sleeping with open windows, even in the colder months, may increase circulation, lessen the risk of metabolic diseases, and help you look younger by releasing more melatonin (which also helps you sleep better).
On a somewhat less related note, I've heard from several people that the healing process in Germany is much slower than it is in the states. Not sure what founded this statement... possibly something about weather, lack of vitamin D or something along those lines, but I can say that post-surgery with the warmer temps, the extra time I've spent outside or sleeping with the windows open may be what has kept my recovery on track!
Don't underestimate the benefits of breathing good, clean air (and take steps to keep it nice and clean)!