In the latest weekly report from Maricopa County Public Health, the county has seen a total of 40 heat-associated deaths so far this year, with hundreds of other deaths still under investigation.
Additionally, 272 county deaths are "under investigation" for heat causes, according to the latest information from county officials.
It appears the majority of the heat-caused deaths occurred in July with a large portion of deaths "under investigation" for heat causes happening within the last six weeks.
Of the total this year, four were "indoor" deaths and all of those incidents either did not have their air conditioning unit on or it was not functioning.
At the same time last year, officials reported 27 heat-caused deaths and a significantly lower number of deaths under investigation, which was at 122.
Over the last six years, Maricopa County has seen an increase in the number of heat associated deaths, with heat-caused deaths seeing a steady climb.
For the latest information on heat-related deaths, visit the Maricopa County Public Health's website.