Missouri is bracing for a potentially dangerous round of summer heat.

The National Weather Service has issued an excessive heat warning or watch for much of the state through Saturday.

In northeast Missouri and western Illinois, high temperatures in the mid to upper 90s and high humidities will combine for heat index values as high as 108.

Friends and relatives are encouraged to check on the elderly. Those without air-conditioning are encouraged to go someplace that has it.

Authorities also warn that pets and children should not be left unattended in cars, even briefly.

The hot spell is expected to break next week. By Monday, highs will drop to the mid 80s.