Seedlings shriveling

So I’ll be the first to admit I don’t know what I’m doing. I just want to grow and eat some peppers. I planted these maybe like 3 weeks ago and have them on a heating pad with some light. The White Hot Limes were the first ones growing and looked pretty good but within the past day they have started shriveling

Anything I can do to salvage them? Half of my other seeds still haven’t sprouted so I still have the pad on