Ambient air temperature of ~70º should be fine.
I suspect a few hours at a higher temperature - 80º - might be fine too.
But ambient air temperature is often not nearly as high as the temperature in a vehicle that's been in the sunlight for a few hours, so that should always be a consideration.
But then if one doesn't have a vehicle or one's purchases won't be in direct sunlight for any length of time, then nevermind.
I suspect a few hours at a higher temperature - 80º - might be fine too.
But ambient air temperature is often not nearly as high as the temperature in a vehicle that's been in the sunlight for a few hours, so that should always be a consideration.
But then if one doesn't have a vehicle or one's purchases won't be in direct sunlight for any length of time, then nevermind.