Surface temperatures must be between 50 and 90 degrees Fahrenheit (10 and 32 degree Celsius) before attempting the installation. As a general rule, if the surface is hot to the touch it's over 90 degrees Fahrenheit. Adhesive becomes brittle when it gets too cold and gummy when it gets too hot. Applications outside the recommended range of 50 to 90 degrees Fahrenheit reduce the adhesives' ability to perform.