Way to calculate the dangerousness level of volts+amps? (don't want to learn the hard way)
NEC code puts a voltage limit of exposed conductors at 48 VDC or 34 VAC sinewave. Current is more of a hot-wire issue, not a shock issue.
Volts times amps is watts, so if not a shock hazard it could be a burn hazard.
A 25 watt solder iron will burn you as it is confined resistive heat. In this case the volts and amps that drive it are not so important.
Note that the NEC voltage limits assume worst-case conditions where a persons hands and feet could be wet, thus much more current could penetrate the body.
The following chart and paragraph are from wiki/High_voltage


The International Electrotechnical Commission and its national
counterparts (IET, IEEE, VDE, etc.) define high voltage as above 1000
V for alternating current, and at least 1500 V for direct current—and
distinguish it from low voltage (50 to 1000 VAC or 120–1500 VDC) and
extra-low voltage (&lt;50 VAC or &lt;120 VDC) circuits. This is in the
context of building wiring and the safety of electrical apparatus. In
automotive engineering, high voltage is defined as voltage in range 30
to 1000 VAC or 60 to 1500 VDC.

I know someone who grabbed phase A and C of a 600 VAC 3-phase surge suppressor. The image of the copper bus bars are forever burned into the palms of each hand. How he survived we do not know.
Because our body acts like a resistor, doubling the voltage puts 4 times the wattage through our body. 480 VAC hits 16 times as hard as 120 VAC.