No, the power suit in the original game has incendiary damage set to 0.0. It is immune to fire and would continue to be so if fire were fixed. This is clearly intentional. The Megapol Armor suit is almost certainly made from either alien alloys or aqua plastics, or some combination of the two - technologies made available after the first and second alien wars. These materials are highly heat resistant. It makes sense that armor made from them would offer considerable fire resistance. I'm not opposed to having regular environmental fire damage Megapol armor and eventually eat through it, but the damage should be very minor.