Just a heads up: You can bring (frozen) beverages through airport security

Full-sized liquids are one of the items travelers most often forget to take out before going through U.S. airport security — the Transportation Security Administration's 3-1-1 liquid rule prohibits carrying liquids, including gels, aerosols, and spreadables, that exceed 3.4 ounces.

Of course, you can take an empty water bottle to the airport and fill it at a fountain after passing through security, but if you want to enjoy a drink from home on the plane, there's another option.

According to TSA regulations, travelers are allowed to bring frozen liquids through security, as long as they are "frozen solid when presented for screening."

Items that are "partially melted, slushy, or contain any liquid at the bottom of the container" must comply with the standard 3-1-1 liquid regulations.

An exception to this rule is breast milk, which can be carried in quantities exceeding 3.4 ounces in carry-on luggage. This is beneficial for nursing mothers, as the TSA allows milk, formula, and pumped breast milk through security without limits, classifying them as "medically necessary liquids."

According to the TSA, "Formula, breast milk, toddler drinks, and baby/toddler food (including puree pouches) in quantities over 3.4 ounces or 100 milliliters are allowed in carry-on luggage and do not need to fit within a quart-sized bag. This also applies to cooling accessories for breast milk and formula, such as ice packs, freezer packs, and gel packs (regardless of whether breast milk is included). Your child or infant doesn’t need to accompany you to bring breast milk, formula, or related supplies."

Regarding the amount you can bring, the TSA specifies "reasonable quantities." Summer Hull, a content director at TPG, notes that this gives individual officers some discretion.

In her experience, there seems to be an unwritten cutoff when children reach about 2 or 3 years old. At that point, the TSA often stops allowing families to bring other liquids through security, even if it's a drink intended for a child in your group. To prevent any liquids for your child from being discarded, she recommends using the frozen method as an alternative.

"Although the TSA regulations allow frozen liquids to pass through security, and I can confirm that it generally works in practice, some TSA agents may interpret the rules differently than most. So, it’s wise to be familiar with the regulations to avoid having your drink discarded," she advised. "I also wouldn't recommend bringing a dozen different frozen drinks unless you're prepared for a secondary screening."