This portable, battery operated (2 x AA batteries, not included) frother from La Cafetière is great for both warm and cold milk. Simply place it into the mug of milk, slide the switch and let the tool take control. Its rod and coil are made from rust-resistant stainless steel.
It also won't transfer different flavours or a metallic taste to the milk that's being frothed. Coming in a fetching red colourway, it's a stand-out frother.