The Maricopa County Health Department has added 19 more people to the Valley's record heat-related death toll for 2017.

Earlier this year, the health department reported 155 deaths, a record for Maricopa County.

With more cases completed, that number has now grown to 174, double the total from a record set more than a decade ago in 2006.

So far this year, epidemiologist Kate Goodin with Maricopa County can confirm 18 heat-related deaths, but said 132 cases are still pending.

"The medical examiner takes several weeks to several months to clear any one case, because they're waiting for pieces of information to come back," Goodin said.

Of the outstanding cases, Goodin predicted, "There's a chance many of those will get confirmed," but added, "we need a little time to finalize those numbers."

Goodin said adults over 75 are always vulnerable to overheating.

However, she warned that middle-age adults between 50 and 64 are also at high risk, which she attributed to underestimating the effect of high temperatures as one's health changes.