Cities must adapt to aging populations and mitigate the effects of climate change and urbanization on health. This study analyses the outdoor thermal and acoustic comfort of older adults in public spaces in Madrid. We compared the subjective perception with real environmental conditions measured in-situ and two thermal comfort indices Physiological Equivalent Temperature (PET) and Universal Thermal Index (UTCI). Additionally, use and stay of older people in those public spaces was assessed. Results showed that older adults represent 26.35% of the users, environmental variables such as mean radiant temperature, air temperature, and noise levels are the most relevant variables for them to decide to stay in these places. Although most of the 413 interviewees perceived the environment as comfortable, this research shows that in dense urban areas there is a significant health risk due to noise pollution and extreme temperatures. Average noise levels measured exceed the maximum threshold recommended by the World Health Organization and according to PET and UTCI indices around 73% of the interviewees would be in risk of thermal stress in winter and 98.2% in summer. The need for further research to find strategies to mitigate the environmental risks of older people in public spaces is evident.