I rented two of these for an outdoor wedding in August. It was hot (for us anyway, in the Northwest, 85+ degrees). Not ONLY did these coolers keep the drinks cold, they lasted through the night and into the NEXT day when we returned to clean up the site. I had no idea I'd still have ice water and frosty Arnold Palmers (ice tea/lemonade) STILL available for the clean up crew nearly 20 hours later. Truly amazing.