Issued within 24 hours of onset of the following conditions: 1) Heat index of at least 1050 F for more than three hours per day for two consecutive days 2) Heat index of more than 115o F for any time period
New York City Government, New York City Natural Hazard Mitigation Plan, Appendix B: Glossary, New York, USA 2009. http://www.nyc.gov/html/oem/downloads/pdf/hazard_m itigation/appendix_b_glossary.pdf, (ND/ Gen - Amer) {894}