Yes it is very dangerous to smoke while you're wearing a nicotine patch to quit smoking.
So while it can be hard at first to stop smoking cigarettes while trying to wean off the cigarettes using the nicotine patch you should not smoke while wearing the nicotine patch.
If you do smoke while wearing a nicotine patch you can get and overdose of nicotine which is very dangerous to your health and can cause death.
So never smoke while wearing a nicotine patch to avoid a nicotine overdose.