1. A computer-implemented method for enhancing thermal design of a physical system having a plurality of boundary values, said method comprising the steps of: determining an initial spatial power distribution P t=0 at an initial time t=0; incrementing said time t by a time step t step less than a characteristic thermal time constant of said physical system to obtain an incremented time value; representing thermal response of said physical system to said plurality of boundary values at said incremented time value as a superposition of temperature fields associated with given ones of said boundary values, based on a previous spatial power distribution at a time equal to said incremented time value less said time step t step , said previous spatial power distribution comprising said initial spatial power distribution for a first increment; obtaining at least one constraining parameter for said incremented time value; calculating a subsequent spatial power distribution P t at said incremented time value, wherein said subsequent spatial power distribution P t both satisfies said at least one constraining parameter for said incremented time value and provides a minimum temperature distribution; repeating said incrementing step for a plurality of repetitions to obtain a plurality of subsequent incremented time values; wherein: at each of said repetitions, said steps of representing thermal response, obtaining at least one constraining parameter, and calculating a subsequent spatial power distribution are repeated to obtain a transient analysis, said transient analysis comprising a plurality of said subsequent spatial power distributions, calculated at each of said plurality of subsequent incremented time values, in which at least some of said subsequent spatial power distributions are time-varying; and at least one of said boundary values comprises a time-varying power source; further comprising applying said time-varying power source to said physical system in accordance with said time-varying subsequent spatial power distributions.