An encaustic paint film is stable in a temperature range of approximately 40-120°F. Wax is more fragile in the cold and becomes extremely brittle in freezing temperatures. If you would drop the painting is cold temperatures it will shatter. The paintings will begin to shift at 120°F. The wax begins to be workable at 150°F, and it becomes liquid at 162°F. Very hot days can soften the wax somewhat, but will cause no real damage.
If you must transport the painting in hot or cold weather simply first cover the entire wax surface with wax paper, then cardboard, and some form of insulation. When that painting is at room temperature remove the wax paper and unwrap the painting. When in hot weather the wax paper will stick to the painting but will cause no damage as long as it is removed at room temperature.
Do not hang your painting in direct sunlight. You should never put any fine art in direct sun, but with encaustic there could be more immediate consequences. If you are nervous about the placement of the painting just feel the surface. If it is warm the painting needs to be moved. It should always feel cool to the touch.
I usually avoid glassing an encaustic piece. If encased in glass and hung in direct sunlight, the glass will magnify the light and the space between painting and glass can heat up dramatically causing the painting to melt and shift. The paints have a damar resin in its formula; this cures and hardens the wax over time making the paint less vulnerable to damage. It's like varnishing the painting from within...so it doesn't need glass. However, you can still take your fingernail and scratch the surface.
You will need to buff your painting when it seems dull or hazed over. The painting should always be shiny. When the painting is "young" or recently finished, it has not yet had time to cure and harden. It will therefore go back to a matte looking surface after buffing the first few times. As time goes by and the mixture has had a chance to cure and harden, (could take up to 6 months) it will keep its buffed polished look. At this point, it also sheds dust and dirt more readily. When the painting is at room temperature or cooler take a soft 100% lint-free cotton cloth(they are used for buffing cars) and buff the painting like you would buff a waxed car. Do not buff painting if it is over 75 degrees. Do not buff hard enough to create heat.
Encaustic paints are perhaps the most durable form of painting, evidenced by the Faiyûm mummy portraits in Egypt, which have survived over 2000 years without cracking, flaking, or fading. Wax has several inherent qualities that allow it to withstand the test of time: it is a natural adhesive and preservative; it is moisture resistant, mildew and fungus resistant, and unappetizing to insects. Wax paint also does not contain solvents or oils so they will not darken or yellow with age. Leaving the painting as fresh as the day it was painted.