Essential tremors are common with ms. Different from Parkinson's which happens at rest, the essential tremor happens when holding or reaching for something. I've had it in my left hand since at least 94, long before I ever decided to see a neurologist in 2014.

I have noticed my right hand/ arm shaking while I was eating, I was also wondering if this was MS or something else? I have had this off and on several times.

Mostly stressful and fatigue cause my hand tremor to go seismic.

In the summer the heat and humidity level pretty much dictates what I do. I begin to become uncomfortable around 75 degrees. The more humid the more sluggish, weak, and dumb I become. If it's 80 or more and there is something going on outside, I'm out. My symptoms intensify, my turns to mush, I feel sick, hand tremors get worse too. Showers sometimes wipe me out. Heat = inflammation and inflammation plays a large role on setting everything in motion.
Your head shaking may be a muscle twitch. I get them in random parts while I'm trying to go to sleep. My hand suddenly jumped off my chest and came back down. Various parts of my body will twitch about 30 seconds apart.
Cold does not seem to bother me but I have heard other people say that coldness causes them problems. So you are definitely not alone. My body thermostat is completely out of whack and I am a slave to it.