Telecare is the remote or enhanced delivery of care services to people in their own home or community setting using ICT. Telecare is expected to play an important role in addressing some of the challenges of an ageing population. However, products are often unsatisfactory and a major contributing factor is that suppliers do not typically involve users in design processes. This paper describes a participatory design project involving 25 designers, 6 service users, 11 potential future service users and 2 telecare suppliers: six concept designs were created for a wearable alarm button in two half-day workshops. Our main contribution is to present the design features considered most important to users, which can be incorporated into future product designs and inform other wearable alarm systems for older people. As a result of the project, a leading supplier has invited users to participate in their research and development activities for the first time.