Some actions intended to adapt to climate change may do more harm than good, especially when they consume energy, making it more difficult to shift to decarbonized energy, or when, in meeting the needs of one group of people, they increase the vulnerability of others. Heat wave risk provides a typical example : air conditioning (AC) equipment may trigger large energy consumption and worsen heat stress outdoor. Alternative adaptation strategies exist, but it is not clear whether they can prevent AC from being massively used. Here, with an interdisciplinary modeling platform, taking Paris as a case study, we provide a first quantified analysis of the efficiency of adaptation strategies (large scale urban greening, building insulation policy, generalized behavioral changes in AC use) in reducing future potential AC need. We find that even ambitious strategies do not appear sufficient to totally replace AC and ensure thermal comfort, under a median climate change scenario. They can, however, reduce AC energy use by half during the heat waves and compensate for the heat releases outdoor. Our results show that adaptation actions, implemented early, may play a key role if we are to remain on a low-carbon pathway.