Nicotine is not a persistent or pervasive poison. If you get a mild nic poisoning effect, i.e. an "overdose" on Monday and you're alive on Tuesday, there will be NO long-term effect. I've gotten a troublesome O.D. on nicotine twice in 3 years. Once, when I was starting and had not discovered I need WTA, because I kept vaping trying in vain to get satisfaction. It gave me an anxiety attack. Unfortunately, my reaction to anxiety is to want to smoke, and I KNEW that would NOT help, of course. So I got some 0 nic and vaped that until the anxiety went away. The anxiety lasted quite a few hours, until I had a REALLY BIG Indian all-you-can-eat meal, which ended the attack.
The second time, I was hanging out with chain-smoking relatives for 18 hours and got a similar effect, but had not brought my 0 nic with me. So that was torture, 'cause I wanted to SMOKE, or at least vape. I cut down on vaping (I couldn't stop), took a nap, then had another huge meal (Thanksgiving this time) and then was OK.
Trust me, if you're getting too much from vaping you'll feel like crap LONG LONG before there is ANY reason to get treatment for it and LONG before your long-term health is in danger (with the possible exception of people already in bad trouble with their hearts, who should probably avoid anxiety attacks) but if you've had this happen, I strongly recommend carrying 10 ml of 0 nic in your kit unless you have the will power to avoid oral satisfaction when anxious.