A lamp would be fine. So long as the chick does not get too hot. You could even use a desk lamp for example over a box.
He is sounding like he has many problems if you feel his left side is not right either, for me in this situation I would cull him. I know it sounds harsh and I've had to do a few of my own when they have just not hatched right. Not all of them hatch well and healthy.
This is just my opinion and what I would do if it were my chick. I'm not saying you should, I can't make that decision for you. But I would consider how the chick is now, do you believe there is a chance he will recover?
He is sounding like he has many problems if you feel his left side is not right either, for me in this situation I would cull him. I know it sounds harsh and I've had to do a few of my own when they have just not hatched right. Not all of them hatch well and healthy.
This is just my opinion and what I would do if it were my chick. I'm not saying you should, I can't make that decision for you. But I would consider how the chick is now, do you believe there is a chance he will recover?