CHICAGO — McDonald’s is bringing back its Spicy Chicken McNuggets on September 1 for a limited time, and the response from the American public has been, by all available measures, the response of a country that has been waiting for this specific bite for years.

The nuggets return to participating restaurants nationwide starting September 1, with a spicy tempura coating made with aged cayenne and chili peppers, according to the chain’s announcement. They will be offered in the usual sizes — 6, 10, 20, and 40 — and they will come back with a friend: the Mighty Hot Sauce, a dipping sauce of crushed red pepper and spicy chilis with garlic and a hint of sweetness, which is a description that reads, on paper, like a dare from a friend you cannot refuse.

That is the part nobody is talking about. The nugget is a known quantity. The sauce is a variable.

Dennis O’Malley, 58, who has been eating McNuggets at the same O’Hare-area location for “probably 25 years, give or take a recession,” was in line when the announcement went up on the kitchen TV.

“I don’t even like spicy food,” he said, holding a tray like it was a life raft. “My wife doesn’t like spicy food. My dog has a strong opinion about spicy food. But when I saw the 40-piece, I had a feeling. I can’t explain the feeling. It was like when the power goes out and you’re like, ‘no, no, no, it’s fine, it’s fine.’ It’s fine. I’m getting 40.”

The city of Naperville, Illinois — population roughly the size of a very serious nugget order — announced it would celebrate the return with a community event, a decision the mayor described as “logistical.”

“At some point the math works out,” Mayor Linda Kowalczyk said at a brief press conference, which consisted of her standing in front of a banner. “We have 136,000 residents. McDonald’s has a 40-piece. Do the math. This is not a food event. This is a municipal readiness event.”

She did not elaborate on what readiness would look like. She did confirm that the fire department “knows the drill,” a phrase that, in her town, has a specific meaning that the fire department has asked not to be discussed.

"I have a system. I have the milk. I have the second milk. I have water, for the part where it gets serious. I have called my mother, who is the final authority on these situations. She said, 'Don't get the 40.' I got the 40."

The quote is from Tyler, 17, who was asked what his heat-preparation strategy was and answered, in a single unbroken sentence, for approximately ninety seconds.

A gastroenterologist at a Chicago hospital, who spoke on condition that his clinic’s waiting room not be described as “full,” offered the medical view.

“The sauce is the variable,” he said. “The nugget is breaded chicken with cayenne. The sauce is garlic and chilis and a touch of sweetness, and the touch of sweetness is the part that makes people think it’s fine. It is not fine. It is a negotiation, and the sauce wins the negotiation.”

THE SPICY McNUGGET: ODDS & OUTCOMES

  • Return date: September 1, participating locations nationwide
  • Coating: Spicy tempura with aged cayenne and chili peppers
  • Accompaniment: Mighty Hot Sauce — crushed red pepper, chilis, garlic, "a hint of sweetness"
  • Available sizes: 6, 10, 20, 40
  • Nationwide milk purchases, week of announcement: "Up," per one dairy executive, who declined to give a number
  • Recommended pairing, per the gastroenterologist: "The 10-piece, and then you stop being clever"

Limited-time items have a way of organizing a community. There is a line for them. There is a strategy. There is a person at the end of the line who got the 40.

At press time, McDonald’s confirmed the September 1 date and declined to comment on whether the Mighty Hot Sauce would be offered in a “Mightier” size, a question the chain described as “an interesting one” and then, in the same statement, moved on.