How to ship supplements and gummies in summer heat without melted orders.

Gummies and other heat-sensitive supplements rarely melt while a truck is moving. They melt when a parcel sits still somewhere hot: a trailer parked over a weekend, a delivery van in the sun, a porch at three in the afternoon. So a summer plan cuts the hours a parcel spends sitting, packs the SKUs that need it for the zone and the month they ship into, and keeps the lot on every order so you can tell a bad lot from a bad week of weather.

Which supplements can't take the heat?

Gummies are the obvious ones. They're gels, held together by gelatin or pectin, and when they get warm they soften, sweat and stick to each other. A bottle that left the warehouse full of loose gummies can arrive as one sticky lump the shape of the bottle. Softgels can soften and stick too, and probiotics can lose live cultures.

Not every gummy behaves the same way. Pectin and gelatin formulas soften at different temperatures, sugar-free recipes behave differently from sugared ones, and a bottle with a lot of empty space lets the gummies shift and press together as they warm. Your manufacturer has the number that matters: the temperature at which your formula starts to soften, from their stability testing. Ask for it per SKU and keep it in your SKU list next to the weight and the lot rules. If they can't give you one, treat the SKU as heat-sensitive until you know otherwise.

Capsules, tablets and most powders in sealed tubs travel fine in summer. That's useful, because your heat plan only has to cover part of your catalog, and the rest of your orders can ship the way they do in March.

Where a parcel gets hot on the way to your customer

A parcel spends most of its trip stopped. It waits on the dock for the carrier's pickup, rides to a sort hub, waits again, rides in a trailer, waits at the local station, and then spends a day in a delivery vehicle making stops before it lands on a step. Each wait is a chance to heat up, and a closed space in the sun heats up fast.

The National Weather Service puts numbers on how fast. Its page on hot cars says that even on an 80 degree day, the temperature inside a car can rise as much as 30 to 35 degrees in half an hour, and readings can pass 100 degrees in as little as 10 to 15 minutes (checked November 2026). A parked delivery van with its doors shut is the same kind of metal box.

The worst wait is the weekend. A parcel that leaves on a Thursday for a long ground trip can spend Saturday and Sunday in a trailer or a terminal that isn't cooled, and then the porch is the last hot spot. Most of what works in summer comes down to fewer days in the network, no weekends in a trailer, and less time on the step.

Who carries the risk when an order melts in transit

Carriers sell transport, and they don't promise a temperature. USPS spells out the default in its mailing standards. Publication 52 defines perishable matter as anything that can deteriorate in the mail and lose value, and says mailable perishables travel at the mailer's risk when they're packaged as required, and must be delivered within appropriate and reasonable time limits to prevent deterioration (checked November 2026). The general packaging standards in DMM 601 ask mailers to package mailpieces to withstand normal transit and handling without breakage or deterioration of content (checked November 2026).

UPS and FedEx publish their own guidance for temperature-sensitive and perishable shipments on ups.com and fedex.com, covering insulated packaging, coolants and which days to ship. Read the version for the service you use before you set a rule. Whichever carrier you use, a melted order lands on you as a reship, a refund or a bad review, so the plan is yours to set.

A heat plan by destination and month

How much protection an order needs comes down to how long it's in transit and how hot it is where it's going. Map your heat-sensitive SKUs against your ground transit times and you get a short table you can hand to any 3PL. This starting version is for parcels that leave northern New Jersey by ground.

The table is a start, and your own data will move the lines. Pull last summer's complaints and refunds for melted product, sort them by destination state and ship day, and you'll see where a liner pays for itself and where it's money spent on packaging that wasn't needed.

How to pack gummies for summer shipping

There are three levels of protection, and each one costs more than the last. Match them to the table instead of packing every order for the worst case.

• The bottle: a bottle sized for its count, with little empty space, a good induction seal and a desiccant if the manufacturer recommends one, keeps gummies from shifting and pressing together as they warm. It's a change at your manufacturer, and it helps all year.
• The liner: an insulated liner or an insulated mailer slows how fast heat gets in. It won't keep a parcel cool for days, but it buys hours, and hours are what a van in the sun takes away. It also adds size to the carton, which can move the postage, and our dimensional weight guideDimensional weight: how the box you choose sets your postage.Carriers bill a parcel on its actual weight or its volume turned into pounds, whichever is higher, so a box with air in it can cost more than what's inside. shows how the box you choose sets what you pay.
• The cold pack: a gel pack, frozen before it's packed, inside the liner. It adds weight, size and a step at the packing station, and it needs a freezer at the warehouse. Seal the gel pack in its own bag and keep it from touching the bottle directly, so condensation doesn't soak the label or the lot code.

Write the rule down per SKU, with the months it applies and the zones it covers. A packing rule that lives in someone's head gets applied when they remember it. Our guide to packaging standards per SKUPackaging standards per SKU: the document that stops damage.A packaging standard is a rule saved on each SKU that tells the packer which box, cushioning and orientation it gets, so every order ships the same way. shows what a written rule contains and how the warehouse system applies it at the packing station.

Ship days, faster services and what to tell customers

Packaging slows the heat down, and timing cuts the hours the parcel is exposed to it. Four changes cover most of it.

1. 01Ship heat-sensitive orders early in the week. Assume an order with a gummy SKU comes in on a Thursday afternoon for a customer in a hot state. If it goes out Friday, it can sit in the network all weekend, while a Monday pickup keeps it moving on working days. Ask your 3PL whether they can hold orders by SKU and destination, and on which days the hold applies.
2. 02Use a faster service for the hot zones. Expedited costs more per parcel, so set it against what a melted order costs you: the product, the reship, the postage twice and the customer's patience. For a subscription with a good margin that's often an easy call. For a single low-priced bottle it often isn't.
3. 03Tell the customer. A line on the shipping page saying heat-sensitive orders ship early in the week in summer, and a note in the shipping confirmation to bring the parcel inside, cost you nothing. Customers who know gummies are on the way tend to move them off the porch.
4. 04Watch the weather where you ship. When a heat advisory covers a big share of your customers, decide for those days whether you'll pause, upgrade the service, or ship as usual and accept a few returns.

Subscriptions need one more thought. A renewal fires on its date whatever the weather, so a Thursday renewal sends heat-sensitive orders out at the worst point in the week. If your subscription app lets you move renewal days, putting them early in the week does a lot of the job for you.

Use lot data to tell a bad lot from a hot week

When complaints about melted or stuck gummies come in, there are two likely causes, and they need different fixes. If the complaints cluster on one lot, shipped to every region and in every week, look at the product first, and that's a conversation with your manufacturer. If they cluster on one region during one hot spell, across several lots, the trip did it, and your heat plan needs a change for that zone.

You can only tell the two apart if every order records the lot that went into it. That's the job of lot tracking at the warehouse: the lot is recorded at receiving and confirmed at pick. The lot tracking and FEFO guideLot tracking and FEFO for supplement brands, from receiving to a recall trace.What a lot is, how a 3PL records lot and expiry at receiving, how FEFO picking works and how a recall trace runs. At YNK we record the lot at the dock. walks through how that runs, from the dock to a recall trace.

Heat matters for stock that hasn't shipped yet, too. A pallet of gummies that crossed the country in a hot trailer may already be soft before a single order goes out. Ask your manufacturer and your freight carrier how the inbound travels in summer, and have the warehouse open a case at receiving to look before the lot goes on the shelf.

Before the first hot week, run through this list with your team and your 3PL.

• Get the softening temperature for each gummy, softgel, chocolate and probiotic SKU from the manufacturer, and add it to your SKU list.
• Mark every SKU as heat-sensitive or not in the SKU list you send your 3PL.
• Set the months the summer rule runs and the zones it covers, using the table above.
• Choose a packing level per zone: standard, liner, or liner with a frozen gel pack.
• Decide which days heat-sensitive orders can ship, and whether a faster service applies to the hot zones.
• Order liners and gel packs before you need them, and agree where the warehouse stores them and who freezes the gel packs.
• Add a heat line to your shipping page and your shipping confirmation email.
• Agree how melted returns get graded and logged, by lot and by destination.
• Pull last summer's melt complaints by state, ship day and lot, and pick the rate you'll watch this year.

How heat-sensitive supplements ship at YNK

We receive supplements and gummiesSupplement fulfillmentLot and expiry recorded at receiving, first-expired-first-out picking, Makks gummy vitamins. by lot with their expiry dates, and picking runs first-expired-first-out, so the sellable lot that expires soonest ships first. Every unit is scanned onto the shelf at receiving, and scanned again against the order before it goes in the box, with the scan confirming the right SKU and the right lot. That's how pick and pack error stays under 0.3% across more than 1.2 million orders a year. Climate-controlled storage is available, and what your product needs in storage is set case by case in your proposal.

Your summer rule becomes a packing rule for those SKUs in the WMS, the warehouse software we run on ShipStation, so a gummy order going to a hot zone gets its liner without anyone having to remember it. Liners, gel packs and cartons are billed as they're used, and your own branded materials are welcome. A one-off job, like repacking a lot that arrived soft, is special-project labor at an estimated $35 an hour, and only when you ask for it.

Orders in by noon Eastern (12pm ET) ship the same business day. Anything later goes out the next business day, or within two to three business days during peak. From our building in Elmwood ParkNew Jersey 3PLThe Elmwood Park warehouse, rates, transit times and directions, 15 miles from Manhattan., ground reaches New York, New Jersey, Pennsylvania, New England and the DC area in 1 to 2 business days and the rest of the country in about 5 business days, with expedited available. Makks gummy vitamins ship from here on that same cutoff.

Returns come back to the same building at an estimated $3.00 per parcel. Each one is received and inspected: sealed, in-date stock goes back to its lot, and opened or damaged product is disposed of by your policy. Handling is an estimated $3.00 per order and storage $0.65 per cubic foot per month, with no seasonal or peak surcharges on handling or storage. Tell us which SKUs are heat-sensitive in the 3PL intake, which takes about ten minutes. Someone from the team replies within one business day, and the proposal follows within five. Inventory ships to 465 Mola Blvd, Dock 10, Elmwood Park, NJ 07407.

Questions founders ask about shipping gummies in summer