Symptoms of Heat Stroke

If your dog has heat stroke he will progressively show these signs:

Excessive panting;
Pale gums, bright red tongue;
Disorientation and your dog doesn't respond to his name;
Increased heart rate;
Thick saliva;
Vomiting;
Breathing difficulties;
Collapse;
Coma;
Death
Treatment

Heat stroke often occurs because a dog is confined, either in a car, kennel or crate; the first thing to do is remove your dog from where he was confined.

Make sure your dog is out of the sun and has access to water but don't let him drink too much.

Cool him with cool/tepid water - either immerse him in a bath, gently hose him or apply cool towels to his body. Importantly do not leave wet towels on your dog and do not use very cold water - both prevent your dog form being able to cool himself.

Move your dog to an area where there is cool air circulating, such as an air conditioned room or stand him in front of a fan. The cool circulating air will help your dog to reduce his temperature.

Keep monitoring your dog's temperature with a rectal thermometer; once it returns to normal stop the cooling process.

Whilst you are cooling your dog down phone your local emergency dog clinic, explain the situation and perform any additional treatment they suggest before taking him to the clinic.

Even if you manage to reduce your dog's temperature at home, take him to your vet for a thorough checkup - internal damage to your dog's organs might have taken place even though he recovered from heat stroke.