Not so isolated

This is how serious they take vehicle interior temperature in the USA http://www.blackthornk9.com/pg18.html

Also, from the following report it can be seen that these incidents involving Police Dogs do happen elsewhere see http://www.wdsu.com/news/20134024/detail.html

Death of Police Dogs

A Notts police officer whose dogs died in last month's heatwave is to face legal action and has been suspended by the force.
The German Shepherds died after allegedly being left in the handler's car at Notts Police's headquarters in Arnold on June 30.
An RSPCA spokesperson said: "The RSPCA can confirm that following the deaths of two police dogs in Nottinghamshire on 30 June, legal proceedings will be brought against a Nottinghamshire police officer for causing unnecessary suffering to the two animals."

2 Police Dogs die in hot car

An investigation has been launched after two Police Dogs died in the handlers own vehicle whilst he was visiting Headquarters last Tuesday afternoon, 30 June 2009.