Electronics and optics of our photo (or video) equipment are relatively sensitive to temperature. This leads us to as the question about its protection against heat. There are plenty of rumours and a lot of bad ideas about the best method to protect your photo camera against heat during a photo safari.
Example of a bad idea: Put the camera in a plastic bag (the type you use in the fridge or the freezer). It hardly limits the temperature (the thickness of the isolating plastic is very small) and you will soon notice that the bag is more a nuisance than anything else without bringing noticeable benefits (after a few minutes only, you will see no temperature difference inside and out of the bag).
It has often been told that the white colour of the high-end lenses from Canon or Minolta-Sony eases their use in very sunny conditions (and that the black colour of lenses from Nikon and others is better for the South Pole). Even if it is formally exact that white better reflects the Sun visible radiation and so reduces a little the internal temperature of the lens, this effect is very small in most conditions. It is more common to say that -for devices correctly handled- the thermal conduction (contact with hot air) is more effective than thermal radiation (exposure to the Sun light).
The simplest is certainly to avoid exposing too much your photo equipment to direct sun light (or limiting it). For example, keep it as much in the shade as possible (think about a sunshade, etc.) But you must never abandon you equipment in an overheated and closed vehicle (think of the same sound advice as givent to the parents of toddlers: Do not leave them in the car in front of the beach). Furthermore, take advantage of the merest wind to cool down your equipment: In a safari open vehicle, there are always locations where the wind is important when driving (but beware of humidity and dust that may come with it if your devices are not seriously air- and water-tight).
One simple and efficient idea (but not always easy to implement correctly): use an insulated isotherm box. If you do not open it too often, it will keep a rather cool interior and will maintain your equipment protected from the external harsh conditions. My father has been using this for years to transport photo devices in long car trips.
But, do not over-do it. Do not include ice, dry ice or any other source of cold/freeze. It could create an enormous temperature difference between the outside and the inside. The cure may become worse than the sickness, with formation of condensation, thermal shocks that would be dangerous for the well-being of electronics, mechanics, etc.
Last but not least, do not forget that there are thermal stress conditions to avoid for your photo equipment: The cargo compartment of an airplae is not a good place for your photo equipment; Putting your camera in front of the outlet of a car air conditionner could bring very dangerous thermal shocks.
Those were the elements of my own epxerience. Yours is now welcome (even more if you have good tricks to apply).