PCMS_Philadelphia_Medicine_Summer2017 - 22

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FEATURE

Summer in the City:
Promoting Health and Safety
in Philadelphia during Extreme Heat Events
By: Jessica Caum, MA, MPH, CPH
Program Manager, Bioterrorism & Public Health Preparedness
Philadelphia Department of Public Health, Division of Disease Control

Hot weather can cause severe illness and death due to heat stroke
or exacerbation of chronic conditions. Extreme heat continues to
be a leading cause of weather-related mortality in the United States.
In Philadelphia, there have been 134 heat-related deaths in the past
decade, with 35 of them occurring in 2011. Heat-related deaths
can be prevented, in part, through raising awareness among at-risk
populations about how to modify behaviors during summer months
when high temperatures pose health risks.
As the climate in Philadelphia is projected to become hotter with
increased frequency and longer duration of extreme heat events,
the Philadelphia Department of Public Health (PDPH) has been
working alongside partner agencies to enhance the city's strategies for
responding to heat events. PDPH did an extensive review of morbidity,
mortality, and National Weather Service data from 2006-2016 to
identify the weather conditions that are most likely to cause deaths.
PDPH used this analysis to redefine thresholds and activation levels
for the city's response actions. When the heat index (a measurement
of temperature and humidity) is above 105°F for two consecutive
days, PDPH will declare a "Heat Health Emergency," which triggers
the activation of several city services, including the Philadelphia
Corporation for Aging (PCA) Heatline, as well as cooling centers.
While the city's response actions can help to save lives, health care
providers also play a critical role in educating patients before a
dangerous heat event occurs.

22 Philadelphia Medicine : Summer 2017

At-Risk Populations
Certain individuals are at increased risk for heat-related illness,
including older adults (65 years+), infants and young children,
and people with chronic medical conditions. Socially isolated and
homebound persons are also at risk. Lower socioeconomic status
may increase risk due to lack of air conditioning in the home or
inability to pay utility bills. Concurrence of multiple risk factors,
as may often occur among the senior population in Philadelphia,
further increases risk for adverse health outcomes.
People with some chronic medical conditions are less likely to
sense and respond to changes in temperature and may also take
medications that can contribute to dehydration (e.g., diuretics)
or interfere with the body's ability to thermoregulate (e.g., beta
blockers). Conditions of particular concern include obesity, diabetes,
cardiovascular, respiratory, and renal disease, as well as psychiatric
illnesses, such as schizophrenia and bipolar disorder.
Geographic location may also influence risk. Due to lack of
vegetation, tall buildings, and concentration of dark, non-reflective
surfaces, there can be significant differences between temperatures in
an urban environment compared to the surrounding suburban area,
a phenomenon known as the urban heat island effect. In the evening,
for instance, the difference can be up to 22°F warmer in a city than
the surrounding area. For people without air conditioning, higher
nighttime temperatures can inhibit overnight recovery from heat
stress, which is particularly concerning during an extended heat event.
https://philamedsoc.org/
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