nbc's chris clacum reports. >> reporter: excessive heat warnings now extend east to new york where there's concern the heat wave could become more dangerous. >> my aunt is 92 years old, and she had a little bit of a heart problem, and her air conditioner broke yesterday, so she needs one no matter what the cost, no matter what. >> reporter: air conditioners and cooling centers are at a premium everywhere with temperatures expected to reach 100 degrees and higher. in ohio, triple digit heat is suspected in the death of a man in a house near columbus where the air conditioning wasn't working. that was one of some two dozen deaths blamed on a heat mass that creeped slowly across the country and at last count set 221 new record high temperatures. in washington, the vacation crowd is getting a lesson in why it's not just the heat, but the humidity. >> humid, hot, muggy, nasty. >> just like soup. yeah. >> reporter: in nearby virginia, civil war buffs reenacting a battle of 150 years ago insist on boiling in authentic uniforms. >> the first men as battle was 100 something, and 50 years it was 100