How the deadliest hazard kills mobile home residents

Mortality is the most serious outcome of natural disasters, which United States experience every year. Surprisingly, the most deadliest hazard is not a hurricane or tornado, but it is the one that sneaks up unnoticed in the middle of a warm summer day. According to the Centers for Disease Control and Prevention, more people die in the U.S. from heat than all other natural disasters combined. Heat has been the deadliest hazard in the USA in the past 60 years with the total 5352 cases from 1960 until 2018. Even though in the context of global warming this problem escalates to the national and international level, its impact remains underestimated. Various studies highlight that the experience and consequences of heat exposure vary drastically depend on the area and socio-demographic factors.

Although only 5% of housing in Maricopa county are mobile homes, 29% historically are sites for indoor heat related deaths. But in 2019, a record year for heat related deaths, 38% of indoor deaths happened in mobile homes.Thus, the residents of mobile homes in Maricopa county in Arizona are disproportionately effected by heat.

Only in the last 12 years, from 2006 till 2018, Maricopa County alone made 24% of total heat-associated deaths from past 58 years in the whole United States. Phoenix is the anchor of the Phoenix Metropolitan Area which is located in the Maricopa County with the total population of 4,485,414 people. Located in the heart of desert, the city of Phoenix, Arizona is the hottest city in the whole United States. With the total population of 1,680,992 people it is the most populous city in Arizona, the fifth most populous city and the largest state capital by population in the United States.

The Phoenix Metropolitan Area experiences high temperatures during the summer period that quite often leads to heat-associated deaths. The alarming 35% of all heat deaths happened indoors, which means that it is challenging to find a proper shelter during the summer. However, hot weather patterns are failed to explain predicted mortality estimates. Explore the chart below to see the differences in predicted heat deaths based on weather and adjusted heat deaths for the past 13 years.

There are 92,031 mobile homes in Maricopa County which is 5.2% of the total housing stock in the county and these residents make up 29% of indoor heat associated deaths from 2006 till 2019. Even though mobile homes take a small part of a housing market of Maricopa County, their residents are disproportionately effected by the heat exposure.

Mobile homes play a vital part in the housing market across the United States as it is affordable housing for millions of people. They are a type of manufactured housing that is produced and assembled in factories and then can be transported to a mobile home lot. Mobile housing makes up 10% of the nation’s housing market providing 8.5 million homes for more than 22 million people. Most of the time, mobile homes are part of mobile home parks where a landlord owns the land and manages the community. Mobile home parks are extremely high dense areas where houses located very close to each other without front- or backyards. On the map bellow discover where mobile home parks are concentrated in the Phoenix Metropolitan Area and how they look like.

The demographics of mobile home residents in Maricopa County is very different from residents in other types of housing. The table bellow illustrates demographic comparison of mobile home households on national level and in Maricopa county with single-family households. Thus, median household income of mobile home residents on national level is very low that results in almost a quarter of this population living below poverty level. Even though mobile home residents in Maricopa county have higher median income than the ones on the national level, it is still 65% less than median income of single-family households. In addition, mobile home residents both in Maricopa county and on national level are older than single-family residents. In general, mobile home households in Maricopa county are younger with higher income and lower percentage below poverty level than the ones on national level. But still they are disproportionately effected by heat, which allows to assume that in other counties mobile home households can be effected even more.

Since weather patterns are failed to explain predicted mortality estimates, it is fair to say that heat itself is not a direct killer. It is rather the lack of opportunity to mitigate the heat and stay resilient to it. In Maricopa County, people who lived in mobile homes and perished from the heat are twice as likely to not have had AC present as those who died in dwellings other than mobile home parks. For mobile home dwellers who did have AC present in their trailers and died from heat related effects, they were three times more likely to have their electricity turned off versus residents who passed away in other home types. (MCPHD 2006-2018; KER 2019).

Heat exposure is a challenge for mobile home residents because of the high electricity bills due to the extreme temperature. One way to build resilience and support the vulnerable population is utility assistance programs. However, according to the KER survey, the majority of mobile home residents, 76.2%, have never participated in a program to help pay home energy bills. There are some challenges that prevent mobile home residents to participate in such programs. As long as the mobile homes are part of the mobile home park community, the electricity bills usually go through the park management system. This means that mobile home residents are not direct customers for electricity companies, so they cannot apply directly. Also, mobile home residents do not own the land under their homes, which can be an obstacle to plant trees. The installation of the solar panels also can be a challenge due to the poor roof construction of the mobile homes. In contradiction, single-family homeowners have no challenges like this as they are flexible in managing their property.

The use of the AC increases the use of electricity. The previous KER analysis of the residents of mobile homes found out electric bills can be a financial burden for the mobile home residents during hot summer period. Mobile homes usually are very leaky as they have poor insulated construction. Mobile homes get hotter faster than regular homes and can maintain the same temperature inside as outside. Thus, it requires more electricity to cool down mobile homes. As a result, 39% of mobile home residents spend more than 10% on the electricity from their monthly budget during the summer. For some people, this percentage can reach 30-50% of their entire budget in summer. In contrast, single-family home residents pay less than 10% with the average 2.60% in Arizona.

Due to a very limited budget and low income mobile home households are forced to use less electricity or not use it at all to afford electricity. As a result, in more than 30% of cases of indoor heat deaths in mobile homes the AC was not functioning because of the no electricity. In other cases it was not functioning or not in use. Numerous previous studies showed there is a correlation between the use of electricity to run AC and heat-related incidents. This can explain a high number of heat morbidity among mobile home residents. The map bellow illustrates the gap between utility assistance and heat related deaths. Zoom in to the highlighted area to see high number of mobile home and indoor heat deaths along with lower utility assistance cases.

During summer 2020 Knowledge Exchange for Resilience organized Heat Resilience Challenge with the goal to find solutions to mitigate heat exposure of mobile home residents. The ideas were developed by ASU students from the Law School. Solutions provide variety of methods and approaches in technological, social and policy-making aspects. The technological solutions include the following:

Since the heat exposure of mobile homes is a very complex problem, it requires complex approach with ideas from various aspects. Thus, there were developed solutions based on the social and policy-making approach:

The Phoenix Metropolitan Area experiences great heat exposure during summer months resulting in high mortality numbers. Unfortunately mobile home residents in Maricopa county are disproportionately effected by heat. The reason for this is poor construction of the mobile homes along with the low income that leads to the higher unaffordable electric bills. Same time utility assassinate programs are designed excluding mobile home residents. Even though the experience of Arizona with severe heat may seem not relevant for the majority of places in the USA, global warming suggests the opposite. In light of this, the heat exposure of mobile home residents requires special attention and approach to mitigation.

Berisha, V., Hondula, D., Roach, M., White, J. R., McKinney, B., Bentz, D., Mohamed, A., Uebelherr, J., Goodin, K. (2017). Assessing Adaptation Strategies for Extreme Heat: A Public Health Evaluation of Cooling Centers in Maricopa County, Arizona. Weather, Climate, and Society, 9 (1): 71-80.

Chow, W. T. L., Chuang, W-C., Gober, P. (2012). Vulnerability to Extreme Heat in Metropolitan Phoenix: Spatial, Temporal and Demographic Dimensions. The Professional Geographer, 64 (2): 286-302.

Harlan, S. L., Declet-Barreto, J. H., Stefanov, W. L., Petitti, D. B. (2013). Neighborhood Effects on Heat Deaths: Social and Environmental Predictors of Vulnerability in Maricopa County, Arizona. Environmental Health Perspectives, 121(2), 197–204.

Knowledge Exchange for Resilience (KER). (2019). Improving Heat Resilience among Economically Insecure Phoenicians through Knowledge Exchange.

Maricopa County Public Health Department (MCPHD). Heat Mortality in Maricopa County 2006 - 2015. Heat Surveillance & Mortality Reports. Office of Epidemiology: Phoenix, Arizona. Retrieved from [ https://www.maricopa.gov/ArchiveCenter/ViewFile/Item/3392 ]

Phillips, Lora; Solis, Patricia; Wang, Chuyuan (Carter); Varfalameyeva, Katsiaryna; Burnett, Janice (2020). "Hot for Convergence Research: A Community Engaged Approach to Heat Resilience in Mobile Homes". Geographical Review.

Putnam, H., Hondula, D. M., Urban, A., Berisha, V., Iñiguez, P., Roach, M. (2018). It’s Not the Heat, It’s the Vulnerability: Attribution of the 2016 Spike in Heat-associated Deaths in Maricopa County, Arizona. Environmental Research Letters, 13 (9): 094022.