I put these in a side pocket of one of the coolers we took to the 500, then promptly forgot about it. It lasted all day in 96-degree heat and being crushed between and underneath things to and from the track. I found them the next day when I was cleaning up, still largely undestroyed, but feeling a little squishy, so I put them in the freezer. I was surprised it didn’t come out as chocolate mush! Oh, and these are the coconut M&Ms by the way, and they’re delicious, even when somewhat squished!