Transient receptor potential (TRP) channels are ubiquitous occurring cation-selective sensory ion channels that respond to various stimuli. Here the authors characterize crTRP1 from the alga Chlamydomonas reinhardtii, present its 3.5 Å cryo-EM structure and show that crTRP1 opens in response to increased temperature and is positively regulated by the membrane lipid PIP2.