An underrated perk of living in NYC this time of year? The luxurious, complimentary saunas that come with every subway ride. Simply head down any staircase you can find on the street, tap your OMNY card, and enjoy the full-body sweat experience!
Kidding, of course. The heat inside NYC’s subway system is often less than ideal this time of year, with some stations getting significantly hotter than the temperatures above ground. It’s an inconvenience that can range from your makeup melting before you even make it to dinner to a genuinely serious health concern during extreme heat.
But the MTA and city officials are now looking at a pretty clever way to fight back: using all that excess subway heat as a resource instead of letting it go to waste.
NYC officials announced Monday that they’re exploring a new thermal energy network that could pull heat from sweltering subway stations and store it underground, where it could eventually be used to heat nearby city buildings during the winter.
Considering one of those stations has averaged 96°F during the summer, we’d say there’s certainly no shortage of heat to work with. Here’s what to know!
The Problem: Why Are Stations So Unbearably Hot?
Subway platforms act as massive heat traps during summer months due to a few compounding factors:
- AC Waste Heat: Train air conditioning units keep passengers cool inside the cars, but blast hot exhaust directly onto enclosed platforms.
- Train Dwelling: Stations like Brooklyn Bridge–City Hall generate extra ambient heat from trains sitting at terminals (like the 6 line) with idling engines and systems.
- Century-Old Infrastructure: Built over 100 years ago, deep-set subway hubs lack modern ventilation and were never designed for today’s extreme climate conditions.
- Extreme Temperatures: The Brooklyn Bridge–City Hall complex averaged 96°F during peak summer months, with platform temperatures occasionally touching 100°F.
The Big Fix: The Chambers Street Revitalization Project
The heat-busting plan is also part of a much bigger makeover for the 113-year-old Chambers Street J/Z station.
Funded through congestion pricing revenue, the top-to-bottom renovation will bring structural repairs, new tiles, upgraded stairways, and long-overdue ceiling and water-damage fixes, with a construction contract expected by the end of 2026.
Even better, the station’s abandoned center platform gives engineers a rare opportunity to test geothermal technology without disrupting passengers—making Chambers Street an ideal place to see if this futuristic cooling plan can actually work.
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How It Works: Thermal Energy Networks & Radiant Cooling
This initiative marks the first Thermal Energy Network (TEN) installed in a U.S. transit system. The technology is already proven in hospital campuses and universities, but applying it underground is a game-changer.
- Step 1: Radiant Cooling Panels: Instead of relying solely on heavy traditional AC, chilled water circulates through panels in ceilings, walls, or floor tubing. Radiant cooling is 25% to 35% more energy-efficient and directly absorbs platform heat.
- Step 2: Thermal Boreholes: Piping routes the captured heat to geothermal boreholes drilled deep into the ground beneath the abandoned Chambers Street platform.
- Step 3: Underground Storage: The subterranean rock acts as a giant heat battery, trapping thermal energy safely through the autumn.
- Step 4: Winter Building Heat: When temperatures drop, heat pumps pull that stored thermal energy back up to heat nearby city municipal buildings, slashing reliance on fossil fuels and lowering city energy bills.
The rollout won’t happen overnight, but the MTA and city are officially getting the ball rolling.
An $800,000 feasibility study is slated for fall 2026 to determine whether the geothermal system can work, including how much cooling it could provide and whether the site is suitable. By late 2026, the MTA plans to award the contract for the Chambers Street J/Z station’s major renovation, with design and engineering for the thermal network potentially beginning in early 2027 if the study gets the green light.
And Chambers Street may just be the beginning: the MTA is also exploring similar cooling solutions for other notoriously hot stations, including the 168th Street and 181st Street stations on the 1 line, where the goal is to bring summer platform temperatures down to roughly 82°F–85°F.
Part of a Bigger Climate Strategy
The subway heat plan is just one piece of NYC’s larger push to become more resilient as temperatures rise.
The city’s Urban Forest Plan aims to increase tree canopy coverage to 30%, while more than 130 solar installations are already planned or underway at public schools, with dozens more in the pipeline. Meanwhile, NYC is also accelerating the transition to electric municipal vehicles, with the goal of fully electrifying its Sanitation, Parks, and enforcement fleets by 2030.