From NWS:

...WIND CHILL ADVISORY IN EFFECT FROM 1 AM TO 11 AM EST
WEDNESDAY...

* WHAT...Very cold wind chills expected. Wind chills as low as
  20 below zero.

* WHERE...Portions of central, east central, north central and
  west central Indiana.

* WHEN...From 1 AM to 11 AM EST Wednesday.

* IMPACTS...The cold wind chills could cause frostbite on exposed
  skin in as little as 30 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use caution while traveling outside. Wear appropriate clothing, a
hat, and gloves.