I have to recommend a product I recently purchased... it isn't too hot in VB (yet), but we have AC and we use it liberally here.  Up in Blacksburg, though, we don't have AC and the summer is only a little cooler than it is at the Beach.  X:  So, I bought this product in anticipation of moving back to BBurg for work or for school, whichever comes first.  

Anyways, the product I ABSOLUTELY LOVE is 

The K&H Cool Bed III

We have the medium one for Waffle and it fits him just right.  He's a pretty big boy (ideal weight is probably 33 pounds but he's only 30) and it encompasses his whole body stretched out.  It says up to 60 Pounds, but if you're really desperate to cool, it holds my 145 pounds just fine.  

It really, really works.  It uses the properties of water to control heat transfer from the dog to the bed.  Water takes a lot of energy to heat up, and it also likes to be the same temperature as what is around it.  So after a night of sitting in the cool house, the water will be room temperature.  Because the dog's body temperature is 102, room temperature is usually 20-30 degrees below the dog's body temp.  So, it feels cool to the touch.  The water will not heat up when the dog sits on it, because the dog is simply not putting enough energy into the water with his body heat. The water will till try to be in equilibrium with the dog's body temperature, though, and it will still suck the heat out of his body and into the water in the bed.  

The bed is made from a nylon/vinyl mix.  It doesn't leak or feel damp, though when you first fill it up, it will look that way.  The plugs are sturdy and look like they will hold up for a long time, barring any chewing.  But, the plugs are supposed to face the floor, so only really creative chewers will manage to find them, probably.  There is a foam center in it (they try to fool you and say it has a special gel core-- it doesn't), and with the water in it, it's more than an inch thick and is very comfortable to lay on.  It says it would be good for dogs with orthopedic issues, and I'm inclined to agree.

When you put your hand on it (or lay on it, as I am wont to do) it really does feel cool.  After a hard play time, I got Waffle to lay on it and he looked pretty comfy.  But, then he got TOO COLD and had to get off and curl up on the couch. Haha.  I imagine that in places that don't use the AC all and the room temp is 80-85 degrees, it would be very useful.  The maximum temperature it says the bed can be at is 95 degrees.  Obviously, the cooler the better.  It's for outdoor use, too, and they recommend leaving it over an AC vent over night and putting it in the shade during the day.  

The downsides? It's HEAVY.  The medium one holds 3.25 gallons of water, so moving it around is a little hard.  It smells like you would expect it to smell-- like vunylThere's also the very real possibility of it getting punctured.  You're supposed to check under the bed every day for any leaks.  If the fabric or plugs are damaged after usual wear and tear, there's a 2 year warranty with receipt.  

I love it, it works, and when the weather warms up, maybe Waffle will love it as much as I do too!