Which can affect your skin faster, getting burned by steam or boiling water, both at 100 degree Celsius?

With steam there has been a phase change from a boiling
liquid to a hot gas so the steam has more energy than the boiling liquid. You first have
to remove enough heat to condense the heat to boiling
water.

If you get boiling water on your skin the skin
immediately starts absorbing heat from the water and in the process starts cooling the
water;

If you expose your skin to steam, the skin first has
to absorb enough heat energy to convert the steam to boiling water, then the skin will
continue absorbing heat to start cooling the water.

So, the
steam can cause much more damage to your skin than boiling
water.