The Covid shot did this to me. Heart rate was almost hitting 150, I was uncontrollably shaking and so cold/clammy they couldn't keep the EKG stickies on me. They thought I was having a pulmonary embolism since I got J&J the day before. Had to go through all the tests to make sure it wasn't, was forced to stay over night because they couldn't discharge me until my BP and heart rate went down to safe levels. It wasn't a PE luckily, just a reaction to the vaccine.

I'm not anti vax but when it came time for boosters it was a hard fucking no from me. Also, the hefty ER bill for the visit due to the reaction to a mandatory (for my job) vaccine didn't sit to well with me, either.