What counts as 'hot work'?
Any work involving open flame, sparks, or heat capable of igniting nearby combustibles: welding (arc, MIG, TIG, oxy-fuel), cutting (plasma, torch, abrasive), grinding (cutoff wheels, angle grinders), soldering and brazing with open flame, and some adhesive applications using open-flame heat. Inside a designated hot-work area (a permanent welding bay with appropriate fire protection), the permit isn't required.