Designed for cold water performance, this Women’s KONA Thermal Long Sleeve Rash Guard works as either a stand-alone thermal layer or as an extra insulating layer worn under a wetsuit. It provides excellent warmth even when wet while absorbing minimal water, helping you stay lighter, warmer, and more comfortable for longer sessions.. Popular with surfers, open water swimmers, triathletes and cold water watersports users, this thermal rash vest provides both insulation and wind resistance, making it an essential piece of kit for year-round water use.. Ideal For. Cold water surfing and shoulder-season sessions. Open water swimming & triathlon training for added warmth without bulk. Stand-up paddleboarding and kayaking where wind chill becomes a factor. Coasteering, sailing and general watersports in cooler conditions. Layering under wetsuits to extend your usable season. Warmth Without Restriction. The Thermotech microfibre lining traps warmth efficiently while maintaining flexibility. A water-resistant outer layer reduces evaporative cooling, helping you stay warmer between sets or during rest periods. Anatomically shaped panels and 4-way stretch construction allow unrestricted movement for paddling and swimming.. Technical Features. Polypro Thermotech lining provides excellent insulation using low-bulk microfibre fabric. Quick-dry microfibre lining improves comfort between sessions. Durable water-resistant coating improves warmth and water-wicking performance. Flatlock stitched seams for breathable, comfortable construction. 4-way stretch with anatomically shaped panels for efficient movement. Second-skin performance fit across abdomen and shoulders. UV protection (UPF 50+). Fit tip: Choose a close fit for maximum thermal performance under a wetsuit. Size up if you prefer a looser fit when wearing as a stand-alone top.