Heat might not be an issue...were the containers hot? If it was halogen or incandescent light thst was very close to the container you might have some issues but I think humidity level is more of an issue. Most warehouses in FL thst have supplements are not air conditioned and sit in 90 degree temperatures all day and night. In fact, any retail store in florida probably buys from the Europa warehouse in Orlando which is hot and humid. Its up to the brand to seal the container properly and avoid issues. Anyway...If you touch the container and its hot to the touch, like 90+ degrees I would probably avoid it. When I sold supplements I would do a shake test and if the powder sounded loose it was good to go...if you hear clumps or what sounds like rocks...avoid buying it. Hope this helps.
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