Homographs are words that are spelled the same regardless of pronunciation (they may be pronounced the same or differently). Homonyms are words that are both spelled and pronounced the same. Therefore a homonym is both a type of homograph and a type of homophone. To be correct I believe the Venn diagram should have one circle labeled homograph and the other labeled homophone. The intersection should be labeled homonym.
An Excessive Heat Warning is issued when heat indices are expected to reach at least 105 degrees, except at least 110 degrees over Delmarva and far southern New Jersey (Salem, Cumberland, Cape May, and Atlantic Counties).
Know the terms used by the National Weather Service during extreme heat: Heat Wave, Excessive Heat Watch, Heat Advisory, Excessive Heat Warning, and Heat Index. Stay out of the sun. If you must be in the sun, wear sunscreen (at least SPF 15) and a wide-brimmed hat.