There are a number of household items that are affected by humidity and extreme heat.  Wooden furniture: Humidity attracts mould and can cause the wood to deform.  Candles: Made of wax, candles will melt under extreme heat. Fine Art & Paintings: Humidity causes a chemical reaction that causes fading and corrosion on metal frames. Metal: High humidity can cause corrosion and rust. Electronics: The inner workings of electronic devices can cause irreparable technical issues.  Other items that need a temperature controlled storage environment, include DVDs, Vinyl Records, Photos, Books, Musical Instruments, Cosmetics and Medical supplies.