Why is denaturation dangerous for the body?

Denaturation causes loss of enzyme activity which is necessary for biochemical reaction.

Hence many biological process(respiration,digestion,excretion) won't work properly.

Explanation:

Enzymes : These are biological catalyst made of proteins.E.g Pepsin, tyrosine (human digestion)

Denaturation: loss of Quaternary ,tertiary and secondary structure of proteins and nucleic acid because of extreme conditions of temperature , pressure ,pH etc.

When denaturation occur enzymes loss their specific structure, so they can't carry out various life process (e.g respiration, digestion ,excretion).

Enzymes are involved in all biological reaction and work only at optimum temperature ,pH and pressure(human body condition ).