Depending on what time of year you experience a natural disaster, planning for heating and cooling can literally save lives and at the least can help limit discomfort. For heating, if having a generator is not an option, make sure to at least have lots of extra blankets, and perhaps some sort of wood-burning stove or fireplace to use for extra warmth. Plan to sleep in a central area of the home, bundled close together for added body heat. You may find some more ideas for Emergency Heat Sources here
For cooling, it is a good idea to have multiple hand fans in your home. Also consider what type of clothing may be best for reducing heat. Research the direction of prevailing winds in your area so you can open the correct windows in your home to get drafts flowing. You can also cover windows with dark blankets to minimize the sun heat.