My dogs are in here on the bed chilling in the AC. They simply can't take this siriusly.

All languages have expressions like that which are funny. In French, when someone sneezes, the first time people would say: "A tes souhaites!!!", which means "to your wishes!!!", if they sneeze a second time, it's said: "A tes amours!!!", which means "to your loves". I wonder how many expressions like these started.

Yeah, I hate the dog days of August. Just let me stay inside til this passes.

Here’s another example. We live in a very right-handed world. Why is that? In ocular terminology, the left eye is written as OS. Os is Latin for “eye.” So Os Sinister refers to the left eye, because, in Roman days, left-handedness was seen as the mark of evil. In many ancient Mid East societies, where meals were taken communally, a thief had his right hand cut off, because it was not allowed to put one’s left hand into the communal food bowl, because that was the hand used to wipe oneself after defecating. It was common practice, even as late as the 1950’s, that if a child used a crayon with their left hand, mothers put the crayon into the child’s right hand. Most left-handers write with their wrists severely flexed above what they were writing...there were no left handed desks in school, so left-handers could only find wrist support by writing in that cramped fashion. Don’t want any left-handed desks...it only encourages them.

Now at the present time with COVID 19 sneezing means run as fast as you can.

I borrowed a line from Seinfeld. When someone sneezes, I say, "You are SO good looking!"

It goes back at least to the time of Homer....
[nationalgeographic.com]

I've used that expression all my life and had no idea of the origin, thank you. The real origin is so much more poetic than the one I presumed.

And, yeah, it's hot. I tend to avoid outdoor activities until evenings during the dog days of August and sometimes September.

"That's my cup of tea!" An old British expression.

"Be still my heart." A once poetic exclamation from the Romantic period, it can be used when your hearts skips a beat.

I tend to go for "gesundheit" rather than "bless you" being, you know, a godless heathen.

Like the Ring around the roses song, it's about plague and the certainty of death.
Ashes, Ashes, we all fall down.
Words so disturbing the grateful dead used them.

I live in Phoenix, AZ. It's dog days for most of the year.

I usually respond to a sneeze with "You are sooooo GOOD LOOKING ! " -- the Seinfeld response.

Like "Indian Summer," except that one is still a mystery. It originated in North America in the late 18th century and had something to do with Indians, but the exact original meaning/origin is unknown. Language is fun.

I still say bless just as a courtesy lol

When I sneeze I usually say "Aww SHIT" while sneezing so I rarely get any one to bless me any more...lol

As far as a response to someone another person sneezing I do not have a go-to phrase, it also depends on how they sneeze also. The people who do the little baby sneezes I might say something about where is the sick cat or something. I had a friend who sneezed real hard and I made a comment about that amount of pressure I would worry about it coming out of the other end at the same time...

Why say anything at all? There's no response when someone coughs, burps, clears their throat, etc... so why did sneezing require its own response? Also, saying "God bless ytou" to an atheist is just going to start an argument.

For this reason, everyone who knows me have long since gotten used to responding when I sneeze with "Hope you don't die."

It is my understanding that people said bless you because they thought when you sneeze, your spirit was being expelled, maybe because of the spray somehow resembling a ghost or spirit. Thus, they would say "god bless you" because they thought your spirit had exited your body and you needed to be blessed by god to restore you spirit or soul or salvation. Makes sense if you were living in a thatched hut during the 14th century.

Patch Adams named his teaching Hospital "gezhundheit" a rip snorter of a funny place to heal or die

I always heard it to be the other way round, people said Bless You or God Bless You when you sneeze because it was believed that demons might use the opportunity of your momentary incapacitation to slip in and possess you. Blessing a person after they sneezed was meant to give a divine protection against demonic possession.
Abracadabra is a word we often associate with Magic Tricks and Magicians but the root of the word is Abraxas which is a Cabalistic god who is the balance of good and evil, of amorality.
I find that the English language is the most cannibalistic of languages because it steals and morphs words from other cultures and languages without apology and make them its' own. Words like Kamikaze or Wundabar or Gesundheit are often recognized by Anglophones as being English words when they most certainly do not have their roots in the English language, let alone the American language - whatever that is. lol

My family always said “gesundheit!” when someone sneezed. A Pennsylvania Dutch thing. Means “health!”

So I didn't look it up but as its origin native American by chance?

I always heard that saying "bless you" to a person who sneezed meant they were momentarily in between life and death. How would that work and be applied if they were swimming under water? Maybe too long of a period of time. IDK.
As for "dog days" my aunt always said we could not go swimming in creeks or rivers coz it was August and therefore something about dog days. I suspect this did not stop dogs from swimming at all. I'm not sure dogs are superstitious.