Schematic Correx
In the February 2018 Q&A
column, the incorrect schematic
was used in Figure 4. Here is
the correct diagram. We
apologize for any
inconvenience.
Don’t Get Zapped!
I really enjoyed Ward
Silver’s recent column on high
voltage and safety. However,
there is a dangerously incorrect
statement: "Better yet, the path
from a hand to a foot doesn't go through the heart."
The hand to foot path most certainly DOES go
through the heart — particularly when it’s from one hand
to the opposite foot!!! See https://www.ncbi.nlm.nih.gov/
pmc/articles/PMC2763825/.
Furthermore, I have been taught and I believe that the
hand to hand path — while certainly dangerous — is not
necessarily the most dangerous. I have been taught (and it
is intuitive) that the most dangerous path is from one hand
to the other foot. This is born out from the following
reference (Section 6. 5 seems to be publicly accessible).
(Search was "electrical shock hand to hand vs. hand to
foot.")
https://books.google.com/books?id=bd7hBQAAQBAJ&pg
=PA102&lpg=PA102&dq=electrical+shock+hand+to+han
d+vs+hand+to+foot&source=bl&ots=qZ4_JHkdMx&sig=u
EtwyGAZNAj TpcXfqq8AzLGsDko&hl=en&sa=X&ved=0ah
UKEwjl9t2g78vZAhUX4WMKHaghByIQ6AEIfjAI#v=onep
age&q=electrical%20shock%20hand%20to%20hand% 20
vs%20hand%20to%20foot&f=false
So, while the classic "hand in the pocket" advice is
certainly good, it is also critical that the feet and legs be
insulated as well.
I strongly urge a correction be published of the
erroneous statement that "Better yet, the path from a hand
to a foot doesn't go through the heart" as it is dangerously
incorrect.
Jay Jaeger
You're right, of course, that there is a path through the
heart between the hand and foot. I probably should have
written that as "doesn't go directly through the heart." I
don't think there are any truly safe current paths through
the body. I've put a note on the N&V website for the article
and to remind folks to keep their feet insulated, too. Thanks
for the feedback!
Ward Silver N0AX
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