For the last few days, I've been ending up in bed in the afternoons, unable to get warm, exhausted and feeling chills. I guess it's PEM, although it seems to just last a few hours and doesn't involve the body crushed pain that is my experience of full-on PEM. Chills are a frequent feature of my experience of PEM, but I searched the forum and I don't think anyone has mentioned them. I think of them as different to not being able to get warm, although perhaps they go together. And they aren't as big as a shiver. They are a sort of tingling sensation travelling across the skin. Googling, it is suggested that the muscles are contracting and relaxing, and that is what it feels like. And it's suggested that the body does this in order to get warm. The thing is, the thermostat in my house says it's 21 degrees celsius, I'm in bed, fully clothed, covered with a feather duvet and a blanket, and holding a cup of hot tea. My son says the house is warm. Healthline says Another source says: An explanation for why people with rheumatoid arthritis and lupus get chills is That's all a bit vague. I'm interested in whether you all also experience chills as part of your PEM. And what exactly the mechanism is for them. Maybe it will give us a clue as to what is happening in PEM.