"It's not the voltage that kills, it's the current" is the phrase. Well, that's just the basis...it's not
entirely true.
Having been shocked numerous times by disposable cameras' flash capacitors...off just a single 1.5V battery...I can say it's not fun. It's not enough to burn your skin...but enough to make your brain "fuzzy" for a couple seconds. I'd compare it to a quick touch to a 120V home circuit (which, ironically, only produces around 10A at idle. High voltage, low current).
Newer flashes show less than 10V to the hotshoe...enough to be unpleasant due to the quick-discharge nature of a flash. Life threatening? Not really. Sweet to have a weather-sealed flash? Ya!