If you asked my dad the top three causes of illness worldwide, here’s what he’d say:

No. 3: Walking around inside the house barefoot.

No. 2: Leaving the house with wet hair.

No. 1: Air conditioning.

I understand not being accustomed to air conditioning. He didn’t grow up with it.In Greece, most homes and some cars don’t have it, even now.

There’s always a hair-raising minute at a Greek hotel just after you first turn on the air conditioning, during which you’re waiting to see what your next few days will be like.

So, no, I’m not particularly shocked that my dad doesn’t want the air conditioning running at full blast all year, even though he lives in the swamps of Florida, where alligators float in his backyard retention pond and the mercury regularly hits 90 degrees.

But it’s not just a personal preference, one that applies to him and him alone. I took my kids to visit him — remember, we’re soft Midwesterners for whom the entirety of May might pass without the arrival of one short-sleeve day — and they were unprepared for his anti-cold air stance.

“It gives me a headache,” he’d say of the air conditioning whenever I tried to move the thermostat from where it was locked at 85 degrees. “It gets onto my neck.”

I’m not sure how temperate air on a person’s neck gives them a headache, but I dealt with the sultry conditions as best I could.

During the night, when I ran the overhead fans at full blast to get some of the thick air moving through the bedroom where the boys slept, my dad would sneak in after everyone else fell asleep and turn the fans off.

“Why do you keep doing that?” I asked. “They’re waking up soaking wet.”

“You’re going to make them sick. You remember that one time he got pneumonia?” he asked, pointing to my younger son. “It’s because you let them walk around the house with no shoes on.”

It’s pointless to explain to my dad that viruses and bacteria cause pneumonia, not toes touching hardwood floors, just like it’s pointless to tell him that having wet hair outside in the summer can’t give you the flu or that there’s no anarchist conspiracy to burn down all the forests in Greece. He doesn’t want to hear it.

“Why is it so hot in here?” my son asked me at one point during our visit, confusion and flop sweat heavy in his eyes.

I braved my dad’s anger and, full of the thrill of disobedience, snuck over to the thermostat. I moved it down to 78, which seemed scandalously low, and the box began to emit an unearthly moan, like a chthonic monster awoken from its centuries-long slumber.

A few minutes later, after the air handlers had started spitting out stale, vaguely cool air that had been living in the vents for decades, my dad walked out of his bedroom wearing a long-sleeved rugby shirt and a striped scarf, looking for all the world like the oldest fan at a Harry Potter convention.

“Fine, I’ll turn it off,” I said, going back to the thermostat as my kids silently pleaded with me to stay where I was.

“No, keep it,” my dad said, teeth chattering. “I’m fine. I’ll just take some aspirin for the migraine.”

His tone of voice told me that, no, he was not fine at all and would soon be unable to talk as he’d have frozen rock solid.