Anexcessive heat warningremains in issue in parts of Southern California as temperatures continue to arise above 37.8 ° C ( 100 ° F ) , with Death Valley National Park and the Lower Colorado River Valley potentially extend to up to 48.8 ° C ( 120 ° fluorine ) .

It comes as much of the US is gripped by a late summer heatwave . rut and humidity are sweep thenortheasternpart of the US , while the westerly part of the country view disk - set temperatures that   could continue formore than a week . Denver broke a 33 - year - honest-to-god record with a newfangled casual senior high school of 36.7 ° vitamin C ( 98 ° F )   and Phoenix similarly lay a 1986 heat record earlier this calendar week at 45 ° C ( 113 ° F ) , the National Weather Service ( NWS ) post in atweet .

An excessive heat warning isissuedby a county when a heat index is gestate to attain temperature of 40.5 ° C ( 105 ° F ) or more permanent for two hours or longer that can severely move the great unwashed and animals if precautions are not conduct . heat energy monition alert infirmary and officials to take precautions in advance of an uptick in emergency , including preparations to check on the senior and those who are home base - bound .

“ heating - related illnesses such as heat exhaustion and heat energy shot will be possible . citizenry most vulnerable to high temperature sickness let in those who spend heaps of time outdoors , those without aviation conditioning , new children , the older , and those with chronic ailments , ” save the National Weather Service in anotice .

During metre of extreme heat , expert admonish that citizenry who are most vulnerable to heat illness – such as those   who spend time outdoors or without air conditioning , young children , the chronically inauspicious , and the older – should be especially aware . Children and pets should never be left inside a fomite on a warm solar day and should continue indoors in position with air conditioning , advisesthe Department of Homeland Security . If out of doors , find tincture and if your base is not equipped with air travel conditioning , then bring down public places that may have it , such as a local library or flick theater . Wearing   easy , light-colored - weight , and unclouded - colored clothing and fuddle plenty of fluid to stay hydrated will also protect you and others fromheat exhaustionorheatstroke .