Science Trivia : The static electricity with a human body may be 20,000 volts.

The static electricity with a human body may be 20,000 v. at the maximum.

Electricity is naturally discharged when humidity is high and the amount of the static electricity collected in the human body decreases. 
It is not generated when humidity becomes more than 55%. 
Static electricity is accumulated easily when dry. 

The intensive attack of static electricity when you remove a sweater has voltage as high as about 3000-5000 v. 
It is said when it is 10,000 volts or more, there is a risk of harmful interference to the body.