YEARS ago we installed an evaporative air conditioner on our roof.
It was the kind where water is pumped over mesh pads while a fan blows air from the outside into the house.
I'm told they work much better in less humid environments out west, and it was still only adequate at best compared to a proper heat pump type air conditioner we have now.
What got me thinking about this was a couple of comments by my clients about their dogs "throwing in the towel" on longish walks lately, and a very sad case where a poor dog had his whole tongue torn out in a fight with another larger dog. It was awful!
That unfortunate and otherwise uninjured dog had to be euthanised because a dog cannot live without its tongue, one of whose many functions is as the dog's evaporative cooling air-conditioner.
Not only is the canine tongue a ladle for scooping fluids, a receptor for gustatory sensation, a swab for cleaning wounds and a grooming implement, it is also, perhaps most critically, an organ of cooling.
Along with lolling in that peculiarly canine way, the tongue can engorge with blood and so increase the surface area available for evaporative cooling pretty much like my old rooftop air-conditioner.
Instead of the fan we have the movement of air across the tongue back and forth by panting.
Like any air-conditioning system it has its limits, and potentially fatal heat stroke can ensue when the cooling system is overloaded.
Remember that dogs have no sweat glands so can't perspire like us.
So just imagine covering yourself completely in cling-wrap (stay with me here), so your sweat can't evaporate, then putting on a fur coat.
Now go for a walk in the hot sun. Hopefully you will have been arrested for deviant behaviour before you collapsed from heat stroke.
The take home message here is to remember that your dog may not be able to cool as fast as you can on hot days.
Wetting them down all over before a walk will help, as will waiting till the cooler early or late hours.