Huffington Post editor Andy Campbell went to Citi Field earlier this month to cover the Mets' annual fan sleepover. Because this event was hosted by the Mets, he came home with a gross rash on his body.

That's a picture of the rash above, which Campbell found on his upper back the next morning. But where exactly did it come from? Campbell figured it out when he remembered that the Mets-themed pillows that were provided at the event had the same grid-like pattern as his rash. Campbell even emailed Bedgear, the company that provided the pillows, to ask them what the deal was. They replied:

From the pattern of the rash, my impression was definitely that the reaction was coming from the fill of the pillow, at the gusset holes where the cover is thinnest. We have had other people with sensitivities to Memory Foam — always so far to the odor, which is typical to any Memory Foam pillow including Tempur-Pedic, etc. — but it is possible to be allergic to the material itself since it is a petro-chemical-derived foam.

So don't go to the Mets annual sleepover. You'll probably get a rash.