The present invention relates to flexible sheath assemblies configured to withstand high amounts of temperature during endoscopic energy delivery procedures, and related systems and methods of use. In particular, the present invention provides a sheath assembly having a flexible elongate tubular body designed with a temperature resistant polymer and/or a temperature resistant braided material. Such sheath assemblies are configured for use in any kind of endoscopic energy delivery procedure (e.g., tissue ablation, resection, cautery, vascular thrombosis, treatment of cardiac arrhythmias and dysrhythmias, electrosurgery, tissue harvest, etc.).
