The study explores the effects of Urban Heat Island (UHI) on urban residents. Using two case studies in Bangkok, Thailand, and Bandung, Indonesia, the study focuses on the effects of UHI on household energy consumption and health and well-being. A survey questionnaire of 400 respondents from each city was employed. The household energy consumption for each respondent was measured using a proxy variable of average monthly electricity consumption. UHI intensity is measured using cooling degree days (CDD) variable constructed from the temperature difference between urban and sub-urban weather stations. The perceived health effect is measured by heat stress, physical health impacts, mental health impacts, and health and well-being outcomes. The data then are analysed through descriptive and inferential statistics. UHI is found to have a positive correlation with the ownership of air conditioning equipment in Bangkok and Bandung and is found to increase the monthly electricity bill. It is also found that UHI has affected the daily lives of urban residents in terms of increasing household energy consumption for cooling and disruption of activities such as working, sleeping, and general health and well-being.