In the weeks leading up to Valentine's Day, about 738 million flowers, 85 percent of imported flowers, come through the Florida airport with Los Angeles coming in second with 44 million, the Associated Press reported.

Before millions of Americans can present their loved ones with a bouquet of Valentine's Day roses, most of the flowers are flown from Colombia and Ecuador to Miami, many in the bellies of passenger planes, the AP reported.

After landing, cargo handlers and customs agents ensure that the deep red petals stay perfect until they reach their final destination, according to the AP. Valentine's Day is a big day for flowers, topped only by Mother's Day, and cargo teams work extra hours ahead of both to ensure on-time deliveries.

The roses, carnations, hydrangeas, sunflowers and other varieties are rushed by forklift from planes to chilled warehouses and then onto refrigerated trucks or other planes and eventually delivered to florists, gas stations and grocery stores across the country, the AP reported.

"There's a spark in the air while loading these," Andy Kirschner, director of cargo sales for Delta Air Lines told the AP. "You know this is going to loved ones."

Worldwide, airlines and air shippers carried about 52 million tons of freight representing $6 trillion worth of goods last year, according to the International Air Transport Association, the AP reported. The amount of air cargo is expected to climb 17 percent in the next five years.

With flowers, as soon as they're cut a clock starts ticking, so when a plane touches down in Miami, the flowers are rushed to a nearby warehouse where a parade of forklifts carry them into giant rooms set at 35 degrees, the AP reported.

Then big vacuums suck the hot air out of flower boxes and bring in the surrounding cold air, according to the AP. In one hour, the core temperature of flowers, vegetables or other perishables drops 46 degrees.

"It's like working in a meat locker," Michael DiBlasi, a Customs and Border Protection agriculture specialist told the AP. "We love our job. You have to, to work in a cooler."

"It's like it cryogenically extends the life," says Nathaniel R. Miller, a supervisor with Perishable Handling Specialists, which operates the Miami coolers, the AP reported.

Before the flowers can be sent to stores across the country, U.S. Customs and Border Protection check tax documentation, ensure that drugs aren't being smuggled and inspect petals and stems for pests like moths, leaf-miner flies and spider mites, which can ruin crops in American fields, according to the AP.