What happens if AC is on for 2 days?

Hardware overheating and constant use

Modern computer components are explicitly rated for constant, everyday use. Unless your setup suffers from significant airflow blockages or poor ventilation, the actual risk of a system overheating under normal operating conditions is very low.

Adequate cooling and proper case design ensure that heat is dissipated efficiently. Maintaining clean vents and functioning fans is usually all it takes to keep internal temperatures well within safe limits.