What is your zapper like? If it has a higher voltage or
a higher duty cycle compare to Dr. Clark's origninal
design, then it has higher power
and you should probably reduce the zapping time to be safe.
People do get neurological damage from exccessive zapping
with high power zappers. see http://www.royalrife.com/zapper727.html
An oven that can make a perfect toast can also burn the toast.
When sending energy into our body we should certainly be
very careful.