Land Rover Discovery 3 TDV6 - Cold Start Issue

This is not a tutorial film, but rather a record of how I start my 2005 Land Rover Discovery 3, 2.7 litre diesel that has a cold starting issue. I think the glow plugs have failed (in fact I now know that they have), but it might be a problem with the temperature sensor or the engine management system. I need to investigate further. I hope it is not failed glow plugs because I hear they often snap when being removed, resulting in costly repairs. There are specialist glow plug removal firms, but they are expensive. By heating the temperature sensor, I am able to start my car in emergency situations. I use a hair dryer, but if that's not available, even pressing a cup of hot water next to the sensor might be enough to get the car going.