Remaining hydrated for up to 4 hours, this Evaporative Cooling Vest helps maintain a healthy body temperature at work. Soak in cold water and enjoy cooling relief and comfort. Use in construction, landscaping, assembly, iron/steel fabrication and more. High-visibility yellow also provides more safety. Activated polymer-embedded fabric inside brings cooling power to your torso. The outer layer is made of quilted nylon while the exterior is made of poly. Mesh side panel offers improved ventilation and stretch. Design also features V-neck closure, water-repellent liner and black cotton-poly elastic trim. Activate by soaking in water for 2 to 5 minutes. Lightweight, durable, washable vest is reusable. Simply soak in water to reactivate. Size medium fits chests from 36" to 38".