To ensure that a vehicle's **tires** are in good condition and function correctly, it is important to check their **inflation pressure** when they are **cold**. This means that the check should be done before starting to drive, as when driving, the tires heat up and the air pressure inside them increases.

- **Checking the pressure when cold** ensures that the measurement is accurate and aligns with the vehicle manufacturer's recommendations.
- If the pressure is measured when the tires are hot, the air expands, which can give an incorrect reading and lead to improper inflation.
- A tire with incorrect pressure can wear out faster, increase fuel consumption, and reduce vehicle stability. Additionally, improper inflation can increase the risk of blowouts or skidding on wet surfaces.

For these reasons, it is always better to check tire pressure when cold to ensure safe and efficient vehicle handling.