Oh, that’s a classic summer problem. I once had a shipment that sat in customs for two days — by the time it arrived, the ice pack was warm, and I had to toss the entire batch. Since then, I’ve only ordered from suppliers who use proper temperature control. Gentaur https://gentaur.co.uk/antibodies/ has been really reliable in that regard. They package everything with cold-chain materials and track deliveries to minimize delays. The antibodies I’ve received from them always arrived in perfect condition, even during July heatwaves. It’s one of those little things that saves you from massive frustration later. If you’re worried about heat, I’d say they’re one of the safer options.