To heat glass to temperatures of 200-600°C without combustion, resistance heating is a viable method, similar to air heaters. However, achieving the higher end of this temperature range, particularly 600°C, may require alternative techniques. Sunlight can be utilized for heating, but its effectiveness is limited to daytime use. The discussion emphasizes the need for appropriate heating methods based on the desired temperature. Overall, resistance heating is the most straightforward approach for this temperature range.