What is the central idea of this excerpt from The Hot Zone?
Nancy took a breath and gathered her thoughts. She
imagined that passing through the gray-vone door into
Level 4 was like a space walk, except that instead of going
into outer space, you went into inner space, which was
full of the pressure of life trying to get inside your suit.
People went into Level 4 areas all the time at the
Institute, particularly the civilian animal caretakers. But
going into a containment zone to perform a necropsyon
an animal that had died of an amplified unknown hot
agent was something a little different. This was high-
hazard work.
-The Hot Zone,
Richard Preston

Animal necropsies are done only by trained
professionals.

People go into Level 4 areas all the time at the
Institute.

Entering Level 4 is like going into inner space,

Working in a containment zone is very dangerous.