Climate shelters contribute to heat resilience directly, as cool spaces, and indirectly, as community venues for information provision. In a 2025 pilot project in Venice, Italy, we analyse, through surveys and interviews, four possible bottlenecks to shelter use: heat risk perception, awareness of shelters, accessibility, and motivation. We test, through a treatment-control experiment, the impact of information provision in shelters. We find that awareness of shelters is the easiest bottleneck to address. Accessibility hinges on funding and governance constraints. Motivation is context and place driven: green, outdoor, spaces are the most popular, but less well prepared. Risk perception is a crucial policy target, since it drives use and adoption of protective behaviours. Yet, it is sticky: individuals, particularly the elderly, underestimate risk. Information provision did not change risk perception. It, however, increased awareness of shelters and adaptation knowledge. Peer effects and seamless integration of events within community centers promote effectiveness.