Good question Hound, I had these in the 225 F - 250 F range for almost 3 hours if I remember correctly. I took them on a light stomach (not empty, but definitely not full) and had a few beers at the show. Was a lot of fun, but surprised me when I woke up at 5am still buzzed. I might have taken the last 2 between 930-10pm, but I'm not sure...