The magic behind the Chill Maintaining Pilsner Glasses is that they can chill a room-temperature libation to 36° F in just 2 1/2 minutes. This is because of the viscous cooling liquid present between the two layers of the double-walled glasses which freeze after one hour in a freezer. They can keep your beers chilled between 32° F and 36° F for 30 minutes. Durable, borosilicate glass has been used to construct these glasses which can easily withstand extreme temperatures (-22° F to 482° F). Since they have a double-walled construction, your hands will never feel too cold or hot when holding them. Celebrate your beer parties with perfectly chilled drinks served beautifully in these Pilsner-shaped glasses.