DES MOINES, Iowa (AP) — Residents in much of Iowa and Nebraska will continue to broil this weekend as a heat wave persists across the U.S. The National Weather Service has issued an excessive heat warning through late this (Saturday) evening for western, central, and southern Iowa and the eastern half of Nebraska.

Those in the warning areas are urged to stay in air conditioning, drink plenty of water and take frequent breaks from work outside. People are also asked to check on elderly family members.

In Iowa, the weather service predicts the heat index on Saturday could exceed 105 degrees in Des Moines and 102 degrees in Waterloo and Sioux City. In Nebraska, the service says the index will hit 108 degrees in Omaha and 106 degrees in Lincoln.

Strong storms could also hit northern Iowa later today (Saturday).