Reliable and qualified interpretations of palaeobiological records require good knowledge about the (subfossil) organism autecology. Since the introduction of the quantitative transfer functions more than two decades ago, palaeoecologists using space-for-time substitutions have been aware about the high degree of inter-correlations among environmental variables in nature. In the aquatic environment it is still very difficult to disentangle direct (climate) effects from indirect (cascading processes) effects on lake biota. One way to search for response mechanisms and to establish clearer understanding of the requirements and distribution of indicator species, is to conduct controlled experiments in the laboratory. As an example, experiments on respiration physiology have revealed several of the mechanisms behind the successful use of aquatic insects as palaeo-temperature indicators