Background: COVID-19 spreads through direct human-to-human or droplet transmission, and healthcare workers are required to wear personal protective equipment to prevent infection spread and safeguard their health. However, it poses various adverse effects when used inappropriately and for a long time. Objective: to identify the adverse effects associated with personal protective equipment use among critical care nurses during the COVID-19 outbreak. Setting: ICUs at Alexandria New University Hospital and four hospitals affiliated to Ministry of Health, all dedicated to COVID-19 patient care. Subject: The study involved 170 nurses from various ICUs. Tool: The study utilized a tool called "Nurses' Personal Protective Equipment Related Adverse Effects Assessment". The tool included two parts: nurses' data and adverse effects related data. Results: A study found that wearing personal protective equipment impairs critical care nurses' perceptions, leading to weariness, discomfort, and respiratory effects. Most of nurses report discomfort-fitting personal protective equipment. Factors like prior work in isolation ICU, patient assignment, and PPE training contribute to these effects. Conclusion: Critical care nurses face adverse effects from wearing personal protective equipment, including fatigue, discomfort, and skin problems, which negatively impact their performance, physiological needs, and senses. Recommendations: The study recommends adjusting work shifts, nursing hours, and nurse-patient ratios for ICU nurses to minimize personal protective equipment effects. It also emphasizes personal protective equipment training, occupational hazards exposure management, and proper donning and doffing techniques.