A large heat wave is expected to impact a significant portion of the country this week, with local temperatures climbing into the mid-90s.

A multiday heat wave is bringing high temperatures and health risks from the Midwest to the Northeast, prompting warnings and emergency measures.

A heat wave will intensify along the East Coast this week as tropical humidity levels and 100-degree temperatures reach big cities from Boston to Washington. On Sunday, humidity levels were higher in parts of the Northeast and southern Canada than in Florida,