Achieving clear vision through smoke and flames is a highly pursued goal to better manage intervention priorities and to allow first responders operating safely during fire accidents. Here we show active far-infrared systems to image static/moving targets through fire with different imaging performance and field-portability characteristics. Low-coherence infrared systems and high-coherence holographic sensors will be discussed. We show that a pre-trained convolutional neural network can detect the presence of a person hidden behind fire in real-time, accurately, even when the system is not able to reject the flame contributions in full, being suitable for video-surveillance applications.