A cartridge electrical heater is shaped as a cylinder of length \(L=300 \mathrm{~mm}\) and outer diameter \(D=30 \mathrm{~mm}\). Under normal operating conditions, the heater dissipates \(2 \mathrm{~kW}\) while submerged in a water flow that is at \(20^{\circ} \mathrm{C}\) and provides a convection heat transfer coefficient of \(h=5000 \mathrm{~W} / \mathrm{m}^{2} \cdot \mathrm{K}\). Neglecting heat transfer from the ends of the heater, determine its surface temperature \(T_{s}\) and the thermal resistance due to convection. If the water flow is inadvertently terminated while the heater continues to operate, the heater surface is exposed to air that is also at \(20^{\circ} \mathrm{C}\) but for which \(h=50 \mathrm{~W} / \mathrm{m}^{2} \cdot \mathrm{K}\). What are the corresponding thermal resistance due to convection and surface temperature? What are the consequences of such an event?