Extreme Heat Warning

* WHAT...Dangerously hot conditions with heat index values up to 108 expected southwest Iowa and the Omaha metro.

* WHERE...In Iowa, Fremont, Mills, Montgomery, Page, Pottawattamie, and Shelby Counties. In Nebraska, Douglas and Sarpy Counties.

* WHEN...From 1 PM Sunday to 9 PM CDT Tuesday.

* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.

* ADDITIONAL DETAILS...Overnight heat indices in the mid-70s and lower-80s will make it difficult for homes without air conditioning to cool down. Hot weather is expected to persist through the week.