Impacts of birthplace and complications on the association between cold exposure and acute myocardial infarction morbidity in the Migrant City: A time-series study in Shenzhen, China

• Cold exposure may induce AMI morbidity, males, the elderly, and the low-educated are relevant vulnerable populations. • People from southern regions are more vulnerable to cold exposure compared with those from northern regions. • People with hypertension and/or diabetes are more vulnerable to cold exposure compared with those without these diseases.