There's no need to fire-up the stove just for a quick cuppa, simply pop it into the mug of water and plug in.

Many years ago I inherited an old version of this product from my grandmother but it was a  basic immersion heater and the element became frighteningly hot. This new model has a protective guard around the heating element, making it less likely to burn a surface when you put it down after removing it from the liquid. However, it's a little top heavy so you need to position it carefully to avoid the mug tipping over, keep watch as it doesn't turn itself off, put it on a heat-proof surface and leave it to cool down safely after use. Nevertheless, as long as you follow the safety precautions, this is a great little product.