In an emergency situation on an offshore production platform, a Temporary Safe Refuge (TSR) is required to provide life support for a set period until such time that a complete evacuation is carried out. Uncontrolled ingress of smoke resulting from external fires can cause visibility and toxic hazards to personnel inside the TSR. A proper design and location of a TSR with respect to potential fire hazards can minimize these effects. To carry out toxic hazard assessment, AEA Technology has developed a computer code SMILE. This code has been successfully used on numerous existing North Sea installations. The code calculates the build up of combustion products inside a TSR, from which the levels of visibility and toxicity are estimated. This paper briefly discusses the theoretical background to the smoke ingress problem and the application of the SMILE code.