Hi @Nagy26
I’ll probably get shot down for saying it, but a top floor apartment in a heatwave sounds like a pretty miserable situation for any pet, let alone thick-coated dogs who have evolved to survive a cold climate.
It’s great that you’re already thinking of ways to help keep them cool. I think the cooling vests work on the basis that you wet the material, and it has a cooling effect as the moisture evaporates. So the vest does need re-wetting throughout the day otherwise it will become more like wearing a coat for the dogs. The pads that you can freeze might be a safer option, as at least the dogs have the choice of whether to lie on them or not.
On the hottest sit I ever did, the black dog chose to alternate between lying on a relatively cool tile floor indoors, and lying outside on baked earth in full sunlight. No idea how this worked for her, but there was a definite pattern to her behaviour, so it was obviously doing something to help. It was good that she had the freedom to choose what made her comfortable.