If you're taking part in the London Marathon on Sunday, this is your secret weapon. It's a shirt that cools you down by making you hotter. Confused? Let us explain.
It's called The Trick, and it features social structures in the spine that trick the heat receptors in your back into thinking you're much hotter than you actually are. Your body then starts sweating to cool you down. The theory is that because you don't start overheating, you'll protect your energy reserves and be able to perform at a higher level for longer.
That's the theory, anyway. Without having tried it, or have it verified by an independent third-party, we can't say for sure whether it works or not.
By the way, if you are taking part on Sunday and are after some new gear, check out our collection of the best running shoes (opens in new tab) around.
The Trick is made by XBionic, which specialises in this kind of thing. It makes clothing for various sports, including biking, running, golf, motor sports, hunting and tennis. It even makes a shirt modelled on how a beaver insulates itself in cold, damp environments. Can't argue with that.
XBionic also has a range of business clothing, though it's mostly underwear like vests, pants and socks. No doubt they'll help you take care of business. They're the kind of thing we can imagine Archer from the eponymous Netflix series wearing. "Fetch me my XBionic business pants!"
The Trick is available now. The short-sleeved one is £79.99, while the long-sleeved costs £99.