When you receive your whistle or flute it will be easier to play if you warm the instrument up first. Winter shipping makes for some pretty cold temperatures inside the box and a good warmup will prevent the instrument from holding onto all the moisture you are blowing inside the bore. If you do not warm up the instrument, it will respond by bogging down and not having the volume or tone that it should have. The only remedy is to clean the whistle and dry it
out even though it is brand new. I have noticed several makers have started specifying a warm up for their whistles before playing.
If you are playing in a room or outdoors and it is colder than 65 degrees, use some method to keep your whistle warm between sets.
Putting your whistle in your sleeve is one method that works well. When playing outdoors in cold weather, I have a dress coat with a long pocket sewed into the sleeve that will hold up to a Low D size whistle. My neighbor made the alteration to the coat for me and it works just great. I think a pocket that used velcro and could be removed would be a great idea.
If you blow the whistle backward from the bottom, the barrel will warm up and the moisture if any will be in the very bottom of the instrument where gravity will make it go away naturally.
I have recommended turning the mouthpiece upside down when playing in windy or cold conditions in several tips articles. Finally, several e-mails have been received telling me what a help this technique is! The amazing thing about inverting the mouthpiece is that the whistle does not know the mouthpiece is upside down and may even sound better! The mouthpiece does not feel funny when turned over and several people have said that it feels more comfortable than
the regular position. An added benefit in inverting the mouthpiece is moisture gets pushed by your breath and pulled by gravity out the sound hole and your whistle plays much drier.