1. Records: Vinyl records can hold up to a great deal of abuse and, although you don't need to worry about removing them from a hot house (unless you're pushing higher than 125), you should make sure they are all upright with even pressure from both sides. No slanting or leaning as they can and will warp, slowly but surely.
2. Exterior Wood Trim: Wood bends and warps with the humidity that's in the air and can quite often cause gapping. Although that doesn't sound like a large threat, if it's letting streams of hot air into your home while you're paying to keep it out, then it can do some damage (as well as letting in bugs and such). Make sure to run your hand around windows and doors to check for leaks.
3. Electronics: TV's, computers, digital cameras, basically anything that requires a charge doesn't like temperatures over 130 degrees. Although it's probably not that hot inside your home, sitting in a direct line of sun it's easy to reach this. Keep them under a towel or in the coolest place possible.
4. Food: Having learned the hard way, exposed storage might look cool, but it can also ruin most things that come packed in oil or are premixed (curry paste, peanutbutter, olive oil). Keep what you can in the fridge or at least packed in a small cooler if it's your only option. It might still be hot inside, but not as bad as out.
5. Beauty Products: Things like perfumes, lotions and your medicine cabinet potions aren't big fans of heat. Some will change smell, melt, separate, or even ex-sponge themselves from their packaging. Consider storing them in your fridge for the hottest weeks of the year. As a bonus, they'll feel great when you apply them.
6. Upholstery: Although fabric is fine in the heat, upholstery does lighten in extreme sunlight, especially when coupled with the temperatures. In addition, any spills or, say, dog toys left on the cushions, will leave an outline. Awesome right? You could upgrade your window treatments to cool things down and keep the light at bay.
7. Artwork: As the heat rises the humidity usually does as well. Make sure surplus artwork is stored flat and often with something keeping it that way in storage. For prints and pieces on the wall, make sure they are pressed tight in their glass so they don't warp. If they do, remove them and place a bath towel over the top and apply a light iron to them (always moving) to remove wrinkles.
8. Plants: Some plants thrive in the heat and welcome the root dry out time, but others fade during these extra hot weeks and days. Try watering them in both the morning and in the evening, being careful to keep the leaves dry to avoid burning or scalding.
Do you have something to add to the list? Hopefully you haven't learned by experience! Share your thoughts below!