If the dogs in danger then yes you can.
Here`s the RSPCA`s advice.
If the situation becomes critical for the dog and the police are too far away/unable to attend, many people’s instinct will be to break into the car to free the dog.
If you decide to do this, please be aware that without proper justification, this could be classed as criminal damage and, potentially, you may need to defend your actions in court.
Make sure you tell the police what you intend to do, why, and take images/footage of the dog and the names and numbers of witnesses to the incident.
Dogs die in hot cars - Health and welfare - Dogs