I've had a form of neuralgia for most of my life, generated instantly by chill air across my forehead. It is especially bad in the cooler produce section of the grocery store, or in Vicki's car with the AC on. I take Gabapentin for it, which helps, but in the summer when the AC is cooling us down I get the headaches from working in my office since I'm in line with the AC vent. So, rather than suffer in silence I made a deflector which has worked wonders. Ta da!