A method for determining parameters for operating a light source within a photo-thermal targeted treatment system is disclosed. The method includes cooling a treatment location, administering first laser pulses at the treatment location, the first laser pulses having thermal energy below a known damage threshold, tracking skin surface temperatures at the treatment location while administering the first laser pulses, estimating a relationship between parameters for operating the light source and the skin surface temperature by fitting tracked skin surface temperature to a correlation model, determining a safe operating range for the light source to avoid thermal damage at the treatment location while still effectively targeting the chromophore, administering second laser pulses at the treatment location, the second laser pulses staying within the safe operating range for the light source, and adjusting the light source according to the tracked skin surface temperatures to stay within the safe operating range.