Learn to limit the spit. Spitters will find that they hate closed reed calls. They will freeze up no matter what but this will help. As others have said, let them thaw out between stands, but I found that throwing them up on the dashboard makes it worse. Really cold calls introduced to really warm heat will make condesation build up on the reed and actually make it worse. I guess if left up there long enough it would take the humidity out though.
If a call does freeze up turn it around a blow gentley back through to warm up the reed. Flip it around and continue. Open reeds definitely are less prone to freezing, but I enjoy the closed reed for certain sounds. IMO
