On the hottest day of the year, anybody who wears a tie or pantyhose downtown on Thursday must be headed for a job interview.

We’ve learned the hard way about the dangers of heat. Back in 1995, as recounted in Eric Klinenberg’s 2002 book Heat Wave, 739 people died during five sweltering days.

The real danger is in sustained days of heat, and fortunately, we’re expecting just one day this time around. It’s supposed to cool off a bit on Friday.

All the same, local officials are doing their thing and warning folks. Temperatures are expected to climb to around 100 degrees, and a heat advisory will be in effect. Cooling centers will be open throughout the city and Cook County.

After getting caught off-guard in 1995, former Mayor Richard M. Daley became the face of the city’s response to the danger of heat in subsequent heat waves. Mayor Rahm Emanuel’s style so far is to stay in the background, but City Hall still sends out extreme-weather text messages and voice-mail alerts, makes well-being checks to vulnerable elderly residents and opens cooling centers and cooling buses.

As for the rest of us, we can all check on elderly neighbors and family.

Other tips: Stay in air-conditioning as much as possible and in the shade if you go outside. If your home is not air-conditioned, spend at least two hours daily at a mall, library or other public place. Wear sunscreen outside, along with light-colored clothes that cover as much skin as possible.

Drink water regularly, even if you are not thirsty. Never leave children or pets alone in the car. Avoid exertion during the hottest part of the day. Take a cool shower or bath if you get too hot.

Most important, should you see anybody wearing a tie or pantyhose, wish them luck on the job interview.