above about 100°F can warp plastic and damage the LCD; if the outside air is
anywhere near that temperature, the internal fans aren’t going to do much to
cool the hot microprocessor and memory.
If the humidity level is very high, internal parts can become wet, which is not
a good thing for electronic parts; high humidity can also cause floppy disks or
CDs to become stuck in their holders. Of course, if the atmosphere is extremely
dry, the chances of electrostatic buildup and discharge are increased; in that
situation ground yourself before touching your laptop, especially after you
have walked across a carpeted floor.
At great extremes of altitude, above 7,500 feet or so, the cooling system can
also be compromised, and the hard drive read/write heads may not be able
to properly float above the disk surface like they are supposed to. (In case
you were wondering, commercial airliners are pressurized so that the air
density is equivalent to a few thousand feet even while the plane is flying as
much as 25,000 to 30,000 feet above the ground.)
That’s not to say you can’t run your laptop in any environment other than a
68° clean room. But if your laptop has spent the last few hours in the cold
trunk of a car, the best practice is to give the laptop a few hours to warm up
to room temperature before turning it on. This avoids condensation buildup
on internal parts and allows mechanical parts to feel comfortable before they
are asked to move. The more extreme the temperature differential, the more
time you should allow the system to come to room temperature before pow-
ering it up.
Being unattractive ..............................................................................
Keep the laptop away from strong magnetic fields that could cause problems
with storage systems and other pieces of electronics. Sources of magnetism
include any large motors (refrigerators, shredders, winches), television sets,
and unshielded audio speakers.
Don’t be a receiver .............................................................................
Stay away from radio transmitters, including commercial sites. Smaller radios,
including cell phones, are not likely to threaten your data but it’s still not a good
idea to place an active transmitter of any size directly on or near your laptop.
If you suspect radio frequency interference from electrical devices, the first
step should be to move the laptop away from the source. Some external
devices can be shielded from interference through the use of a toroidal coil
(a small iron circle) that surrounds the connecting cable; the device may come
equipped with one, or you can purchase a coil from an electronics shop.
Chapter 21: Ten Essential Dos and Don’ts 319