Welcome to frigid Southwestern Pennsylvania, Mr. President. We trust you will have a productive visit in suburban Pittsburgh promoting the economic thrust of Tuesday’s State of the Union Address.

May we be so bold as to draw your attention to a regional matter that has obvious national overtones.

We are in the midst of an illegal drug crisis. Nearly two dozen deaths in the past two weeks, including at least one in Butler County, have been traced to a lethal batch of heroin circulating in Southwestern Pennsylvania.

In Allegheny County, as many as 18 people aged 25 to 51 may have fatally overdosed on the deadly batch of heroin, authorities said.

At least two fatalities in Westmoreland County and one in Armstrong County may be linked to the same batch.

The heroin, which is being sold in bags stamped with the names “Theraflu,” “Bud Ice” and “Income Tax,” is believed to be laced with the powerful narcotic painkiller fentanyl, according to state and local law enforcement authorities.

Attorney General Kathleen Kane said Monday the overdose deaths appear related to one bad batch of heroin. Bags with the telltale stamps have been found by narcotics agents in Allegheny, Westmoreland, Armstrong, Butler, Lawrence and Beaver counties, she said.

The deaths are a stark reminder that illegal drug use is not simply a bad habit or a matter of recreationl choice. It’s occasionally deadly.

Mr. President, your recent statements condoning the consumption of marijuana, and saying marijuana is no less dangerous than alcohol, sent the wrong message to America’s young people.

Granted, marijuana is not heroin — not even today’s genetically fortified strains of marijuana, which are much more potent than the weed you smoked as a teenager. And the trend is for states to consider decriminalization — Colorado and Washington State recently legalized its recreational use.

Your administration has indicated the U.S. government will not interfere with state actions. And the argument that marijuana is a gateway drug that leads some users to more potent and dangerous narcotics, seems to be losing credence.

And yet, the two drugs may be related in at least two ways:

• Marijuana use among teens and young adults has declined in recent years, while the use of heroin and prescription painkillers has been increasing. The trends suggest a drift toward drug highs that are cheaper, more powerful and more available.

• These trends are slowing and even reversing as authorities crack down on illegal prescription painkillers and heroin, and as individual states decriminalize pot.

Maybe your statement is accurate, and marijuana is no more dangerous than alcohol. But we don’t allow teens to consume alcohol, largely for the same reasons we should not allow them to consume marijuana: not-yet mature brains are especially susceptible to damage from mind-altering substances. Just last month, researches at Northwestern University in your hometown of Chicago published a study showing marijuana can alter young brains, not only in the shape but also the function of the brain. One of the lead researchers recommended a ban on all pot use by anyone age 30 and younger.

Marijuana may or may not be a gateway drug, but you made what must be considered by many as a gateway remark, likely to be misunderstood by a multitude of youngsters who look up to you for guidance.

For their sake, maybe you should clarify that statement, or even recant it.