Ford's new Focus has pushed the limits during its development, with the company exposing it to opposing extremes of hot and cold temperatures.
The work is designed to ensure the car's air-conditioning system can cope with whatever customers put the car through whether they live in Finland or Arizona.
As well as taking the new Focus to exotic locations, such as Antequera in Spain, or across frozen lakes inside the Arctic circle, Ford has done much of the work in Essex.
The manufacturer's heat chambers in Dunton are capable of bringing the car down to -40C and up to +50C in an effort to expose any weaknesses.
Part of the work is not only to ensure the system works, but that it works in a way that owners want it to work. In North America, customers like to feel a strong breeze from the air-conditioning, while in Europe the feedback is for systems that don't produce airflow that can be felt.
The new Ford Focus goes on sale in March.