Can a human in a normal astronaut suit designed for the moon, land on Mercury and walk on it's surface. If not what would happen to him/her?
No sir/madam. An astronaut or a cosmonaut cannot walk on Mercury's surface. The reason is plainly simple. During daytime, its temperature surges up to 430 degree C making it 2nd hottest planet after Venus. Whereas, night time temperatures are as low as -180 degree C.
Despite of having ice caps at its polar regions which might seem attractive, its totally not feasible to land there and then mine the frozen ice to make up a base.
For a much more descriptive read, kindly refer this link : What it would be to live on Mercury