This chocolate bar, like many confectionery products, is best kept in a cool, dry place away from direct sunlight and strong odors. The recommended storage temperature for most chocolate is between 15°C and 20°C (59°F to 68°F).
The product's composition includes milk chocolate, which can be sensitive to heat. As noted in the product information, in hot weather the bar may soften or melt, which can affect its appearance and the distinct layers of its internal structure. If the chocolate melts and re-solidifies, it may develop a whitish surface film known as a fat bloom; this does not mean the product is unsafe to eat, but the texture and mouthfeel may be altered.
If your home is particularly warm, consider storing the unopened bar in a cupboard away from appliances that generate heat. Once opened, it’s best to consume it within a reasonable timeframe. For longer storage, a pantry or a cool cellar is preferable to the refrigerator, as refrigeration can sometimes lead to condensation and sugar bloom. If you do choose to refrigerate it, keep the bar in an airtight container to protect it from moisture and odors.