Christie Watson told local news station WCPO she was shocked upon finding a nearly intact ice cream sandwich her son had left outside for 12 hours.
Temperatures are topping 80 degrees in Cincinnati this week.
Intrigued, Watson left another one of the sandwiches outside for 12 hours - and found that the ice cream had barely melted.
"I thought to myself: what am I feeding to my children?" Watson said.
WCPO did a similar test and left Wal-Mart Great Value brand ice cream sandwiches, Klondike bars, and a cup of Haagen-Dasz outside in the hot sun for 30 minutes.
"The Walmart sandwich, though it melted a bit, remained the most solid in appearance, and still looked like a sandwich," the station reports.
Here's what the sandwich looks like after several hours.
Wal-Mart declined to comment to WCPO, but a source close to the company offered an explanation.
"Ice cream melts based on how much buttermilk, butterfat, and cream are in it. Walmart's sandwiches contain less, so they are more affordable," the source said.
In other words, the sugar and starch contents of the ice cream might keep it from melting the way traditional ice creams do.
According to Wal-Mart's website, the ice cream sandwiches contain milk, cream, buttermilk, sugar, whey, and corn syrup.
It also contains "1% or less of mono-and diglycerides, vanilla extract, guar gum, calcium sulfate, carob bean gum, cellulose gum, carrageenan, artificial flavor, and annatto for color."
Ice cream that doesn't melt has gone mainstream before.
In 2009, Cold-Stone Creamery introduced a "no-drip" creamy treat. The ice cream used the same food starch found in Jell-O pudding.
"The modified food starch that sets instant pudding caused the resulting blend to gel rather than liquefy," New York Magazine reported at the time.