How would you recognize and treat heatstroke in your dog?

It's been hanging roughly around 100 degrees Farenheit here for three full weeks now. I've had to be quite careful with my own dog and also had to explain to dogwalk clients why we are going on MUCH shorter walks in these temperatures. Luckily, most of the owners understand what I tell them. But what do YOU worry about when the temps are up near 100F? What makes you think the dog may have heat stress or heat exhaustion/poisoning? And how would you treat it?

heavy panting,dark red gums,tacky or dry mucus membranes,specifically gums,lying down refusing to get up,collapses,thick saliva,dizziness or disoriented.rectal temp.over 104 requires action,over 106 is dire.if you think he has had heatstroke first move him out of the heat,begin cooling him by placing cool wet washcloths on the body especially the foot pads and around head.DO NOT USE ICE OR VERY COLD WATER!! that causes more distress.once the temp reaches 103 stop cooling.offer him cool water but don't force water into his mouth.call or visit your vet right away-even if he seems better. internal damage might not be obvious to the naked eye,so an exam is necessary.i don't worry because i don't leave my dogs out in this heat.I don't really walk them either because the pavement and even grass is so hot that it burns the pads on their paws.we have had 100 plus degrees here too for the last three weeks.feel like temps have been 115 degrees,i go to work in the heat and my dogs stay home in the AC.