Special Weather Statement issued August 21 at 6:23AM CDT by NWS
Effective: 10 p.m. on Monday, Aug. 21, 2017
Expires: 6 p.m. on Monday, Aug. 21, 2017

...Heat Index Values 100 to 105 expected this afternoon over part
of the Quad State region...
Hot and humid conditions will be the rule today, regardless of the
passage of the solar eclipse through the region this afternoon, as
air temperatures top out in the lower 90s.
Heat index readings are expected to reach 100 degrees by noon over
Southeast Missouri. As temperatures rise into the lower 90s, heat
index readings above 100 degrees will build northeast across
southern Illinois and the Purchase area of West Kentucky, west of
the Land between the Lakes. Heat index values at or above 100
degrees will likely persist through 6 pm CDT today.
The rest of the Quad State region will see heat index values top
out in the upper 90s this afternoon.
If you are planning to be outside today for an extended period of
time, be sure to keep hydrated by drinking plenty of water. Look
for opportunities to get out of the heat from time to time, and
into the shade or in an air conditioned building.
Keep watch on those with you that may be susceptible to or
unaccustomed to the heat and humidity, typical for late August in
this region.

See more at NOAA