Then there was smoke! I had moved to sit next to the FAO (Flight Activities Officer) and EECOM (Environmental Support) was right next to him. It was discovered to be smoke coming from overheated electronics. The rules regarding smoke and fire are very serious and constraining! Oxygen masks were donned by the crew and the EVA crew was told to stop working until the fire was put out. Eventually they got it under control by turning off some systems and fans. EECOM consulted with the flight surgeon about the effects of burnt plastic fumes on the crew and what effects there might be.