Approximately when were thermal foggers used in
The thermal fogger was the sprayer of choice in
the early 1960s.
What did the thermal foggers look like?
Pickup trucks were used – a cab and chassis. The
sprayer was mounted on a plate and bolted on the
cab and chassis. The nozzle mechanism cost $500,
which was very expensive back then.
Where were the thermal foggers used?
Throughout the U.S., but concentrated in
California and Florida and along the Gulf Coast.
How frequently, and during what parts of the
year, was spraying typically done?
This varied regionally, but in Florida it was
from April to October and once per week on
average. In the 1960s, when there were
encephalitis outbreaks, an area might be sprayed
several days in a row. Many programs sprayed
all night. Others sprayed for the first 2-3
hours of darkness and the last 2-3 hours before
What prompted the switch from thermal to ULV
A prime impetus for the switch was the fuel
crunch of the 1970’s. ULV did not require oil,
whereas the thermal foggers used 40 or 80
Also, the thermal foggers were dangerous.
The burn unit fired off gasoline with a
sparkplug. A 16-horsepower engine turned the
blower and pump. The thermal fog nozzle was
nearly “superheated” – cherry red when not
The fog was so dense that the front end of the
vehicle would disappear. And the oily
pesticide spray smeared windshields. Both
things contributed to accidents. One of the
most famous involved actress Jane Mansfield.
Occasionally the thermal foggers threw
fireballs. This could happen any time during
the night of spraying, not just at startup.
(Think kids chasing the trucks.)
does the fog machine serve as a metaphor?
The metaphor is a compound one. Not just “fog” –
confusing, mysterious, obstructive. Not simply a
“machine” – rhythmic, controlled, organized. But
a “fog machine” – poisonous, seductive,
pervasive, deadly, distorting, relentless.
I relate the metaphor to the mission of the William Winter
Institute for Racial Reconciliation which
describes prejudice as “systemic and