There are quite a few YT videos about lightening hair with developer only. People who do this usually seem to wrap the hair in foil and putting the hair under a heat source for hours. I remember a vid in which a woman said she went to work and left the hair in the sun.
I saw a thread about it and noticed that someone warned to be careful doing this because it could cause an explosion or fire. I did keep that in mind.
I had no overheating issues when I used this method on virgin hair.
But I tried it on some Bohyme hair yesterday and after maybe half an hr went to check on the hair which I had in foil, plastic bags and tucked into a heating cap. I felt the bag and it felt EXTREMELY HOT!!!. Wayyyy hotter than my heating cap will ever get on its own. I became alarmed and took it right to the sink. The smell was not pretty. I opened the foil and the hair was SMOKING! I noticed many burned hairs after rinsing. I ended up tossing the hair... Anyway, if I had not gone to check that hair... I don't even want to consider that.
Ladies who do this, please be sure to check every 15 mins or so. This method could be extremely hazardous. Do NOT ever do this and leave hair home no matter what a Youtuber tells you lol.
I just wanted to warn folks about this.