It’s called a “diaper bag,” but maybe it should be known as the “worry bag.”

After all, moms and dads fill these ever-expanding totes with just about every remedy known to baby. Who wants to be caught unprepared during a diaper-related disaster or sudden temper tantrum?

And that goes double on a “relaxing” summer vacation or outing.

“Because we’re so on-the-go, our diaper bags function as a portable changing table, portable food court and entertainment center,” says Sandra Gordon, who recently reviewed a slew of new baby products as co-author of Consumer Reports’ recent “Best Baby Products” book.

But over-packing, especially in summer heat, can turn a day with baby into an unplanned workout.

“Kids are like golf,” says Scott Adler, managing editor of babycenter.com. “If there’s something new that tells you it will improve your game, you’ll probably buy it.” That doesn’t mean you have to tote it everywhere, however.

“The key to packing a smart diaper bag is stick to the basics,” he says. “You don’t want to overload. Schlepping a kid is enough.”

To pack light but still keep your bases covered, look for products that are compact and do double or triple duty. Here’s a rundown of some worth considering and their approximate prices:

Keeping clean

The Sunshine Kids Change ‘N’ Go Bag ($12.99) is a large cushioned changing pad with zippered mesh pockets to hold wipes, creams and diapers. It fits inside a standard diaper bag, but also serves as a self-contained bag for short outings.

Mustela’s Facial Cleansing Cloths come in small pop-up packages. Softly scented, they’re sturdy enough for the diaper area, but gentle enough for baby’s face and mom’s. Use sparingly: At $6.50 for 25, they’re pricier than standard baby wipes.

Munchkin’s Diaper Duck ($4.99) holds a refillable supply of plastic bags tightly wound inside. The bags are good for disposal of used diapers, while the duck is (hopefully) good for amusing baby during the change.

For after-change cleanup (or quick wash-ups anytime), Purell hand sanitizer now comes in fragrances (Ocean Mist and Spring Bloom) that mask its chemical smell, making kids less likely to balk at using it ($1.79 for 2 oz.).

Consider adding Kalencom’s On the Go Potty to your travel lineup as your child grows. This folding frame seat with disposable liners fits in a large diaper bag, though you may prefer to stow it in a car or stroller ($9.99).

Dining out

Gordon recommends a cooler bag from Playtex called Fridge-to-Go ($16.99 for the double-sized tote): “You can pack it and put the whole bag in the freezer, instead of just having ice packs,” she says. It’s useful for chilling (and storing) teething toys or pacifiers, as well as bottles, food and drinks.

For mess-free eating, include a few Pampers Pocket Bibsters (disposable, absorbent bibs with leak-proof liners, $3.99 for 16 ) and a Write-On Wrap-Around Placemat new this year from Classy Kid’s “Green and Clean” line ($9.99 for 20 waterproof mats made from environmentally friendly chalk). Each pack of placemats comes with four “CrayAngles” (angular crayons that won’t roll off a table) to keep kids busy.

Sun, fun and safety

For children older than six months, Gordon suggests Banana Boat’s Baby Sunblock Tear-Free Spray Lotion, SPF 50 ($9.99 for 8 oz.). It works for the whole family and stands in for hand lotion or face cream in a pinch. For added sun protection, try Huggies Little Swimmers Sun Sensors ($3.49-$3.99 for 24). These tiny UV-sensitive strips claim to change color when kids are sun-drenched.

Along with a wide-brimmed hat for blocking the sun, Adler suggests packing a lightweight blanket. They’re great for swaddling fussy babies and can serve as a sun-blocking canopy, emergency diaper-changing pad and privacy cover while nursing, he says.

For playtime, Gordon recommends small toys that offer plenty of entertainment, such as LeapFrog’s My First LeapPad Book: Tad’s Silly Number Farm ($15.99). For older babies, she says, “anything electronic keeps them occupied for hours.” For younger babies, pack a toy that doubles as a teether and a cozy blanket with a plush animal attached.

First-aid emergencies are inevitable, so consider Classy Kid’s new Boo-Boo Care line of first aid products ($1.99 to $24.95), which aim to distract toddlers from their skinned knees with cheery items such as Boo-Boo Juice No-Sting wound cleaner, a toy stethoscope and “bravery stickers.”

Finally, Adler suggests mom and dad pack the diaper bag together, so neither one gets caught unprepared while on the road.