Air pollution monitoring, especially using miniaturized and low-cost sensors, has been increasingly adopted across many application areas -including chemical and automotive industries, smart cities, and agriculture -to protect public health and comply with environmental regulations. In this paper, we demonstrate a new security vulnerability that enables adversaries to remotely spoof low-cost air pollution sensors via long-range and highly localized thermal attacks. Modeling the key attack characteristics, we show how adversaries can exploit the temperature-dependent internal calibration process of air pollution sensors to strategically manipulate sensor measurements through induced heat signals, thereby deceiving the sensors. Using inexpensive laser pointers and commercial Nitrogen Dioxide pollution sensors, we design an evaluation testbed and experimentally show the attack's effectiveness in both indoor and outdoor environments.