Leave in car, car locked windows shut, unless was a super hot day, normally am in and out in less than two mins. If can see is a queue then would take in, but normally isn't - I try to do when on my own but not always possible. To be honest until moved to Australia would never have dreamed of taking in with me, we certainly never were as kids - and is only the overheating aspect in Melbourne that would be rare anyway I see as a more dangerous option than crossing forecourt. The smell of petrol makes me feel sick so I wouldn't feel comfortable leaving windows open and as car has air con even though is off when filling, opening window would in 2 to 3 mins have more of a warming than cooling effect.

Apart from heating what are the other dangers if children are strapped in?