A tractor-trailer catches fire on the highway. The first-in company rolls down the highway about 4 miles, parks up hill and out of the wind, and begins fire attack. The tractor-trailer is fully involved, and the firefighters are surrounded by nasty black smoke, fire and heat.

The firefighter on the nozzle is wearing his coat, gloves, pants, hood and helmet. His partner — wearing only his coat, gloves and helmet — looks like he just stepped off the set of “Emergency.” Neither of them are wearing an SCBA. I lost sight of them several times as the smoke blew over them.

Please don’t misunderstand: These are good people, they really are. But they left five perfectly good SCBAs sitting on the engine for absolutely no reason. Time and again, we’re told, “Wear all of your PPE, every time.” But it doesn’t seem to matter, does it? Some people will just never learn. After all, we’ve heard it all before: “I’ve been doing this [expletive] a long [expletive] time, and ain’t nobody going to tell me I gotta to wear an SCBA.”

You’ve been reading about it for that last couple of weeks: Three firefighters nearly die from cyanide exposure in Rhode Island. But it won’t happen to me, you think. Think again. Cyanide is present wherever plastics burn. Just how much hydrogen cyanide will kill you? 5, 10, 15 percent? The answer: a whopping 0.005 percent; that’s five-thousandths of 1 percent. For you hazmatters out there, that’s just 50 ppm. To put that in perspective, a regulation football field can be divided into 57,240 square-foot sections. Now, pick any three of these sections, and you’ll have slightly more than 0.005 percent.

I wonder: How much of that “sick” feeling we get from too much smoke is actually cyanide poisoning? Be careful out there. Wear your SCBA!