I think the critique has been beat enough.

There is a type of stroke which could be made much worse by aspirin, a hemorrhagic stroke. Otherwise known as bleeding into the brain.

But, as so well pointed out, for people with even a smattering of diagnostic skill a stroke and heart attack are not all that easy to mistake for one another.

That said Leigh_Ratcliffe makes a good point about not assuming too much or jumping in too soon. Keeping the person calm and calling 911 is not bad advice. Most city and suburb dwellers are so close to 911 advice and EMT/rescue services that waiting until your advised to give aspirin or for the troops to arrive isn't much of a risk.

There is certainly still some risk of an unknown allergy or unexpected interaction. Some number of people likely to have a heart attack are already on aspirin and/or other blood thinners that could make them very prone to bleeding. So stuffing aspirin into people you happen to think are having a heart attack isn't something you want to do casually. Every therapy and drug has side effects. Don't go off half-cocked.

In more remote locations, or when emergency services are overwhelmed or unavailable, your much more on your own. Assuming 911 still works an