Here is an absolutely imperitive bit of advice regarding heat and cold and how it affects and can kill, your dog. This is what Anne Finch says in her book, "Pet owners guide to the Greyhound". Page 71.
Greyhounds are sensitive to both cold and heat, not having much natural insulation. A dog whose temperature rises to 42 - 43 degrees Centigrade, even for a few minutes (the normal is 38.5 C), can collapse and die. Being left in a hot room or vehicle can cause death within ten minutes. Signs are distress, frantic panting and collapse. It is an acute emergency. Cool the dog as fast as possible with copious amounts of ice-cold water to the head and the back, massaging the water into the coat so there is not a blanket of water over him. Wet towels, a hose, a paddling pool, or a river will all do in an emergency. In hot weather your dog needs water every 30 - 60 minutes to replace the fluid lost by panting. Always carry a two-litre can of water in your car when you transport your dog - you never know when you are going to be caught in a traffic jam in sunny weather.
Following on from the above, here is a list of things to do to protect your dog published by PETA in August 2007. Click here.