Objectives To examine workload, thermal discomfort and heat‐related symptoms among healthcare workers (HCWs) in an Australian ED during the COVID‐19 pandemic. Methods A cross‐sectional study design was employed among HCWs in an ED at a metropolitan hospital in Brisbane, Australia. Respondents provided demographic information including their self‐reported age, sex, height, weight, role (e.g. doctor, nurse), and whether they wore personal protective equipment (PPE) during their shift, rated as either Full PPE, Partial PPE, or usual uniform or scrubs. The workload of HCWs was assessed with the National Aeronautics and Space Administration's task load index (NASA‐TLX). Thermal discomfort was evaluated using scales from the International Organisation for Standardisation. Responders rated their subjective heat illness using the Environmental Symptoms Questionnaire. Results Fifty‐nine HCWs completed the survey (27 male, 31 female, one prefer not to answer). Overall workload from the NASA‐TLX was 64.6 (interquartile range IQR 56.5–73.3) for doctors, 72.5 (IQR 63.3–83.3) for nurses and 66.7 (IQR 58.3–74.17) for other staff, representing moderate to high ratings. Eighty‐one percent reported thermal sensation to be slightly warm, warm, or hot, and 88% reported being uncomfortable, ranging from slightly to extremely. Ninety‐seven percent reported at least one heat‐strain symptom. More than 50% reported light‐headedness or headache and approximately 30% reported feeling dizzy, faint, or weak. Conclusions ED HCWs experience thermal discomfort when wearing PPE. Combined with their workloads, HCWs experienced symptoms related to heat strain. Therefore, careful consideration should be given to managing heat strain among HCWs when wearing PPE in an ED. This cross‐sectional study surveyed healthcare workers' (HCWs) thermal discomfort, workload, and heat‐related symptoms when wearing personal protective equipment (PPE). ED HCWs experience thermal discomfort, moderate to high workloads, and symptoms related to heat strain when wearing PPE. Therefore, careful consideration should be given to managing heat strain among HCWs when wearing PPE in an ED.