Pets travel in a specially prepared area of the cargo hold. It is pressurised and heated to between 50 and 70 degrees F. It is kept dark to help the animals to sleep and to decrease stress. Long haul destinations require the pets to connect with an international flight at London Heathrow. It is possible to fly to some European destinations direct from regional airports but it is important to remember that only London Gatwick and London Heathrow are authorised to receive pets back into the UK under the Pets Passport Scheme. As such it is usually sensible to use these as departure points as well. You should always check directly with the carrier to learn their specific rules and regulations, as well as with the country you are travelling to.