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Recently I was purchasing sleepwear for my offspring. The paperwork attached to one garment informed me that it wasn’t made with flame-resistant material and should therefore be worn snug. Other garments were clearly marked as not being intended as sleepwear because the material it was made out of wasn’t flame resistant. This led me to wonder: Why is my bundle of joy more likely to catch on fire in the middle of the night than during the day when he’s running around in sweat pants and a T-shirt? —New Mommy, Anchorage

What’s the straight dope on children’s sleepwear? In the U.S., children’s pajamas and nightgowns are required by law to be flame-retardant, but I’ve been told the chemicals used to treat fabrics so they meet this standard cause cancer. Is that true? And how likely are children to catch fire anyway? I don’t allow my children to smoke in bed, and I suspect they are more likely to get cancer. Which should I spend more time worrying about? —Befuddled in Boston

I figure I’ll address this issue now, as we’re heading into one of the fieriest stretches on the calendar. While the crown for outdoor fires belongs to July 4, the likelihood of unwanted home fires spikes during the winter holidays—compared to a typical day there are more than twice as many on New Year’s and nearly two and a half times as many on Christmas. Fires started by candles are four times likelier on Christmas, and the combo of wired-up tree, discarded wrapping paper, and roaring fireplace (often in close proximity) can result in the dreaded decoration fire, responsible on average for four times the property damage and almost 20 times the fatalities of an ordinary house fire. In all, from the day before Christmas to the day after, an annual average of more than 12,000 fires nationwide cause about $92 million in damage and 34 fatalities.

OK, enough seasonal cheer. If you don’t get why kids are more susceptible to fire-related injury at night, you’re not thinking hard enough.

(1) At night kids are likely to be—get this—asleep. As such, they’re prone to miss little cues like smoke filling the room, flames licking at the foot of the bed, or, it turns out, a blaring alarm. That’s because, as parents and babysitters will confirm, children sleep differently from adults: to wit, more soundly, with a longer wake-up curve. One eye-opening Australian study reported that a hallway smoke alarm with an at-the-pillow volume level of 60 decibels was able to reliably wake only 6 percent of kids between 6 and 15. And while kids as a group are slightly less likely to die in a fire than the general population, for children ages zero to four the risk is actually 20 percent greater.

(2) Many grown-ups are also partial to sleeping at night, which often impedes them in the crucial task of keeping kids from going up in flames.

(3) Given that little children don’t exhibit the best danger-avoidance behavior even at peak alertness and have thin skin that’s particularly vulnerable to serious burns, it seems pretty reasonable they be sent to bed in duds that are unlikely to catch fire.

And that’s what Consumer Products Safety Commission sleepwear regulations have tried to ensure. Years ago, this meant all clothing sold as sleepwear had to be made from fabric that was flame-resistant, and one common method of compliance was treating ordinary fabric with fire-retardant chemicals. This, of course, meant kids wound up spending a lot of time in contact with those chemicals, and from early on there was concern over possible health ramifications. The fire retardant Tris was found to be both carcinogenic and absorbable through the skin and mouth; the CPSC did the math, saw it the same way Befuddled did, and banned the stuff in 1977. (Many other additives have similar issues—substances called PBDEs, though not used in sleepwear, are found in mattress and furniture foam even though they’ve been linked to learning and reproductive disorders, thyroid problems, and cancer.)

But pajamas treated with such chemicals have all but disappeared, and despite what many believe, current CPSC standards don’t require that kids’ sleepwear be flame-resistant. What it has to be is either (a) made from materials that can pass flammability tests, which include, for instance, most ordinary polyesters, or (b) tight-fitting, with tapered sleeves and legs and no dangling ornamentation. Why? One, clothing that hangs loose is more apt to find its way into nearby flames; two, since tight-fitting clothing has less surface area, it has less contact with the oxygen needed to fuel a fire. So rather than lose sleep over pajama-related fire injuries or pajama-related cancer, suit the brood up in snug CPSC-approved jammies and you’ll have hours to lie awake envisioning the day they get their learner’s permits. —Cecil Adams

Is there something you need to get straight? Take it up with Cecil on the Straight Dope message board, straightdope.com, or write him at the Washington City Paper, 2390 Champlain St. NW, Washington, DC 20009.