Ventilation-perfusion (V/Q) scan is a specialized test that uses a radioactive substance to show the parts of the lungs that are getting oxygen (ventilation scan) and getting blood flow (perfusion scan) to see if there are portions of the lungs with differences between ventilation and perfusion.
Moleskin may be the first commercial blister treatment and prevention product I remember using. My dad always kept some moleskin in his pack and at the first complaint of any hot or sore feet, out it would come.
My toe nails are also curled over, so it can be a bit tricky, but regular cutting helps. I have also found a product called Eulactol Heel Balm Gold to be most effective for very dry feet. It's available at most pharmacies. It's well worth the expense. I was put onto this cream by a podiatrist.