Duct tape is heat resistant to a certain extent. It is intolerant to high levels of heat. It works as a perfect sealant if there is very little heat acting on the duct tape. Its effectiveness is also determined by high levels of humidity.
When the duct tape is exposed to high levels of heat, it begins to wear away. The tape is made from cloth on which an adhesive such as polyethylene is applied. It looks dark grey in color because of the aluminum pigment added to it at the preparatory stage. Once you use duct tape, it is quite difficult to remove it cleanly.