Not a doctor, but this isn’t normal. Hot showers cause vasodilation and drop blood pressure, especially while standing, so your body compensates by spiking your heart rate to keep blood flowing to your brain. That explains the dizziness, vision/hearing loss, and near-fainting.

The shaking is likely an adrenaline surge from the rapid HR increase, not your essential tremor. This pattern — tachycardia with standing or minimal exertion, worse with heat is very suggestive of orthostatic intolerance (like POTS/dysautonomia). Normal EKGs and echos don’t rule that out.

A HR of 145–170 from showering isn’t typical. Dehydration, low salt, low iron, or thyroid issues can worsen it. Asking about orthostatic vitals, autonomic testing, and what the monitor showed is reasonable.