remember if you are concerned at leaving toys in a garage or shed or storage for fear of discolouration, etc those same toys sat in a warehouse, which was at the mercy of the heat/cold for god knows how long before they were bought by you. Some toys sit for years before they're sold through the scorching heat of summer and the cold of winter. It's not like BBTS, HLJ, RK or even TRU have climate controlled warehouses.

As long as they are not subject to extreme temperatures, or extreme repeated variance in temperatures, they'll be fine.