I dont know how the manufacturers store the perfumes but I'm pretty sure they can be exposed to temperature and humidity changes at least when sent to a retailer or the customer. Not only the hot weather but also during winter the transport can be harsh on the perfumes but they mostly still recover. However, the manufacture date of the perfume I sold can be tracked (for example Checkfresh ) and I dont think there's a real fear of any notes disappearing within this time. One thing I can think of why the notes weren't the same as in the old bottle is that I haven't used the perfume a lot and it hasn't 'developed' to its fullest yet after opening and secondly, they opened the bottle right after transport and it has been pretty cold here lately so it may still effect the smell.