My friend has the following symptoms during a 2-3 hour "episode"
-Shakes
-Cold sweat
-weakness
-tremor in voice
-some confusion but still lucid
-Vomits up anything he eats, no nasea at all, his body just rejects anything of sustinence, including drinks other than water
He has had a couple of them, about a month apart. He has to lay down for a couple hours and they pass.
The last one he tested his blood sugar and it was normal, not Hypoglycemia, unless you can have Hypoglycemia with normal blood sugar levels. He is also an avid ecig vapor user, but nicotine poisoning seems more severe, and he uses that thing all day every day without issues.