Skip to main content

NJ Urban Heat Island and Human Health

Stephanie Sharo

sas782@scarletmail.rutgers.edu

Purpose:

Extreme heat is one of the deadliest weather-related hazards facing New Jersey (NJ). This is specifically dangerous in urban heat islands (UHI), which have many negative impacts on human health. NJ communities need to prepare for changes to their local climates and improve their resilience to extreme heat events.

What are extreme heat events?

  1. FEMA considers an extreme heat event to be a period where temperatures are above 90 degrees for at least two days. A heat wave is a period of sustained high temperatures.

What are the health implications?

  1. Heat Illnesses: heat rash, heat cramps, heat exhaustion, heatstroke
  2. Other: heat stresses the heart and kidneys which can worsen different chronic conditions including cardiovascular such as heart attacks, respiratory such as asthma or COPD, diabetes, or mental health.

What are Urban Heat Islands (UHI)?

  1. Definition: UHI are when developed areas have higher temperatures than the nearby rural areas. On average, cities tend to be 1-7°F warmer than the surrounding countryside during the daytime and as much as 5°F warmer at night.
  2. Measured: by the UHI index which is an estimate of the additional heat that local land use factors contribute to urban areas.
  3. Causes: of UHI are reduced green spaces and vegetation, the percentage of impervious surface, the city design, and the density of human activity.

Who is affected?

  1. Risk Factors: lack of air conditioning, working outdoors, age and pre-existing conditions, socio-economic status, social isolation, and homelessness.

Why should you care?

  1. NJ as outdoor workers make up approximately 20% of New Jersey’s workforce; as such, the impact to New Jersey’s economy from this projected loss in earnings power is expected to reach approximately $900 million for New Jersey alone.
  2. The Centers for Disease Control and Prevention recorded an average of 702 heat deaths per year from 2004 to 2018. EPA’s value of statistical life recommends an estimate of $7.4 million. This equates to almost $520 million dollars lost in economic contribution every year due to heat related deaths.

Additional Resources:

  1. NJ’s Extreme Heat Resilience Action Plan (EHRAP), released July 2024
  2. National Integrated Heat Health Information System (NIHHIS) and its associated web portal
  3. NJDEP Heat Hub NJ