On the contrary, I have a variety of the platypus bags and I pour boiling water into them all the time and have never had any problem. I do use a small funnel with the bags that have the smaller opening. I also use the doubled bag (4 liters each) with the ceramic filter in between to filter water after gathering at my camp site. They seem to be very durable and they work great too. I have some platy bags that must be ten years old (maybe not that old but it seems like it) and I still use them...sabre11004