Just to chime in, I live in Boulder, Colorado, where temps a week or so ago were in the low 90s. I wasn't home, but my wife was, when UPS delivered a (non-LP) package on one of those days. She spoke with the driver briefly: a fellow driver had recently measured the temp in the back of his UPS truck at 140 degrees Fahrenheit! So goodness knows how hot those trucks get if air temp is 110+. Probably best to avoid 'Brown' when it gets so warm.
I've gotten a handful of LPs delivered over the past few weeks, but all have been well-packed & delivered by USPS to my shaded front door, so no damage so far (knock on wood!).