I think people are getting in too much of a pickle about dogs and heat these days.
Firstly - the bottom of a paw pad is not the same as the skin on a human hand, it's far tougher. A dog trotting along a tarmac road from a car park in 23 degree heat isn't going to burn them. In fact, having been involved with dogs/knowing hundreds of people with dogs at any one time, I've never heard of anyone in real life who's had their dog burn it's paw pads on a hot pavement, I've just seen one photo on fb that's been shared on repeat for the last 15 yrs, with no actual evidence it was caused by that.
Secondly, hanging around a food fare for a few hours, with access to shade and water, isn't the same as taking a dog on a hike in the heat.
Thirdly, 23 degrees really isn't that hot. Everyone started making a fuss about dogs being out in the heat when it was 30 degrees plus, and now that has turned into people being worried to death if it's anything over 18.
I say all this as a massive dog lover, who's involved with dogs for my job. I wouldn't do anything to put them at risk.