Question

why does stream cause severe burns than boiling point

Answer 1

first of all steam have high temperature than boiling water and it covers a large area when it comes.

Answer 2

Steam causes severe burns than boiling point because of latent heat of vaporization ( it is the amount of heat energy required to change a unit mass of liquid into vapor at atmospheric pressure). Hence, as steam has more heat energy, it can cause more severe burns than boiling water.
Hope it helps