How to Beat the Heat: Expert Tips from Professor Schlegelmilch

New York City temperatures often feel significantly higher than a recorded 100 degrees due to the Urban Heat Island effect and high humidity. Professor Schlegelmilch, an Associate Professor of Professional Practice in Climate, told ABC7 New York that urban materials like asphalt and concrete absorb solar radiation during the day and release it slowly at night, preventing the city from cooling down.

The phenomenon creates a temperature disparity between densely built urban centers and surrounding rural areas. According to ABC7 New York, this effect is compounded by the city’s geography and the prevalence of heat-absorbing infrastructure.

Why does New York City feel hotter than 100 degrees?

The primary driver is the Urban Heat Island (UHI) effect. Professor Schlegelmilch explained that the materials used to build NYC, specifically concrete and asphalt, have a high thermal mass. These surfaces soak up heat from the sun throughout the daylight hours.

Unlike forests or grasslands, which use evapotranspiration to cool the air, city surfaces radiate this stored heat back into the atmosphere. This process continues long after the sun sets, which keeps nighttime temperatures elevated and prevents the city from resetting its thermal baseline.

The lack of vegetation further intensifies the heat. Trees provide shade and release moisture into the air, but the high density of buildings in NYC limits the available canopy cover, leaving more surfaces exposed to direct sunlight.

How does humidity affect the heat index in NYC?

The recorded temperature is only one part of the equation. The heat index, or “apparent temperature,” determines how the weather actually feels to the human body. According to ABC7 New York, humidity plays a critical role in this perception.

High humidity slows the evaporation of sweat from the skin. Because evaporation is the body’s primary method of cooling itself, moisture-heavy air traps heat against the body. This makes 100-degree weather feel substantially more oppressive than the same temperature in a dry climate.

What strategies can mitigate urban heat?

Professor Schlegelmilch highlighted several methods to lower urban temperatures and reduce the UHI effect. These strategies focus on changing the reflectivity and permeability of city surfaces.

Key mitigation efforts include:

• Cool Roofs: Using white or reflective materials on rooftops to bounce sunlight back into space rather than absorbing it.
• Urban Forestry: Increasing the number of trees to provide natural shade and cooling through transpiration.
• Permeable Pavements: Utilizing materials that allow water to seep into the ground, which can help cool the surface through evaporation.

What are the business and infrastructure implications of urban heat?

Extreme urban heat creates direct financial pressures on city infrastructure and energy markets. As the UHI effect drives apparent temperatures higher, the demand for air conditioning spikes, placing immense strain on the electrical grid.

This increased load raises the risk of brownouts or total grid failure during peak heat events. For businesses, this translates to higher operational costs for cooling and potential revenue losses if power instability disrupts commerce.

Furthermore, extreme heat impacts labor productivity, particularly for outdoor industries such as construction and delivery services. The necessity for mandated heat breaks and adjusted working hours to prevent heatstroke can slow project timelines and increase labor costs.

Public health costs also rise during these periods. According to the reporting by ABC7 New York, the combination of UHI and high humidity increases the frequency of heat-related emergencies, which puts additional pressure on city healthcare systems and emergency response resources.