Hats are useful, necessary even in Australia's heat, but also extremely irritating - after all the effort of finding one that fits, you wear it all summer and into autumn, then put it aside in winter. If you just chuck it in the wardrobe then pull it out again in Spring, it's almost certain that the hat will have shrunk and now no longer fits! And of course there's the inevitable shrinkage when you remove a sweaty hat and it contracts as it dries.
Picture: Some of the many hats available in store
As with many things, prevention is easier than fixing. For hat storage, it's always best practice to store a hat on a hat stretcher - or at the very least, something the approximate size and shape of your head. This will minimize shrinkage.
Picture: A Jacaru hat stretcher
If you need to stretch out your hat again, make sure not to go too far at once. Be gentle with your hat! It's best to get a proper adjustable hat stretcher so that you can smoothly stretch in increments. Go from side to side, then front to back, and keep alternating to slowly stretch it out. A good conditioner can help to restore suppleness to a hat and help with the stretching process. Unfortunately, sometimes hats can't be recovered - but it's often still worth trying.