The Parkes radio telescope had issues with fast radio bursts that they couldn't attribute to what they were tracking. Turned out to be a microwave oven in a nearby building where the door was opened before it had stopped.
While I wouldn't subscribe to standing in front will cook you idea, opening the door prematurely does give off radiation. Standing in front of a microwave beam dish may be a different story - knew an ex-Telecom tech who told a possibly tall tale of cooking chicken.
https://theconversation.com/how-we-found-the-source-of-the-m...
The Telecom guy might have been pulling your leg, but microwave dishes are known to be dangerous if you're in the wrong spot in front of them. (The traditional story is that Percy Spencer noticed a chocolate bar in his pocket get melted by the radar set he was working on. However, the effect had been demonstrated at least a decade earlier.)