It’s not the heat, it’s the stupidity. That is, it’s the stupidity of the body’s defense system that results in allergies. You’ve got this great and amazing array of mechanisms that protect your body from foreign invaders. When some harmful germ or poisonous molecule (i.e. a really tiny thing that is bad for you) enters the body, it gets noticed. It’s not "self" and it doesn’t belong and it’s damaging things. The damaged body cells release their dying breaths (so to speak: the biochemical equivalent of "Aaagh! They got me!"). These tiny chemical death cries bring the cavalry to the rescue to kill and clean up those baddies. This is generally a good thing.
Of course, you also take in a lot of things that are not "self" that are also not harmful. You just pass them through, or spit them out, or breath them back out again. Did you ever look at a sunbeam coming in through the bedroom window and see all those bazillions of dust motes floating in the air? And then hold your breath trying not to inhale any of that stuff? And then give up, knowing that you’ve been inhaling that stuff all your life and you’re going to keep doing it and not even noticing it? Man, I try to look at sunbeams from a discrete distance so I don’t suffocate on that stuff.
Most bodies can tell the difference between the harmful stuff and the sunbeam floaters. Allergy sufferers, on the other hand, have some stupidity in their defenses (which we scientists call the immune system). These people and animals have immune systems that go nuts, over-reacting to stuff that’s harmless. Their defenses dump histamine and other chemicals that make them miserable — runny eyes and nose and itching in people, while dogs and cats mostly have itchy skin. It’s not the pollen or the mold or the pieces of cricket nose-hair — it’s the over-reaction of the immune system. The non-allergic individual stands right beside the sufferer, inhaling the same junk and feeling perfectly fine.
This makes for a tricky situation in trying to help these individuals. Their body defenses have gone nuts, over-reacting, making them miserable. Obviously, we’re going to have to shut the defenses down to get any relief. But wait: if we shut down the body defenses, the baddies can come in and run wild. Dang! We’re between a rock and a hard place now, ain’t we? Kind of reminds you of having to sacrifice your personal freedoms to be protected from terrorists. No free lunch, is there?
What’s worse is that the really bad allergy sufferers just keep developing new sensitivities. Last year it was house-dust, ragweed, bread-mold, wool and hippopotamus dander. This year we’ve added oak pollen, bermuda grass, penicillin and chicken salad. You thought we’d just do some allergy testing and move away from whatever we’re allergic to. Alas, the really miserable patients usually have so many allergies that getting away from it all is not a workable option.
So, if your pet is a mass of self-induced scabs, or soon will be (you’ve just purchased an English Bulldog, Chinese Shar-pei, or some other genetically lucky individual), what ARE your options?