* WHAT...This level of heat can affect anyone without effective cooling and/or adequate hydration. * WHERE...Puerto Rico. * WHEN...Until 5 PM AST this afternoon. * IMPACTS...Heat-related illnesses increase significantly during periods of very high heat indices or high temperatures. This extreme heat event poses a severe threat to anyone with inadequate cooling or hydration. These extreme impacts will be most pronounced across coastal sections, lowlands, interior valleys, and urban areas.