Storing your corsage//bout//hair flowers:  if you are picking up your order the day before your event- please store in the original packaging in the fridge- with the caveat that the fridge must be set at 34 or above. If your fridge regularly freezes lettuces//salads it will most certainly freeze flowers and you should instead store them in a basement or somewhere very cool, out of direct sunlight and drafts in its original packaging. 

Outdoor photos: There is no way to prevent flowers from freezing outdoors in subzero temperatures unless you keep them in the original packaging until you get to your event and put them on once you arrive. Keep this in mind if you plan to do outdoor photos.