Question about 1.5 week old chicks - warmth at night

Hello,
I am new to posting here although I've been reading this forum for weeks and enjoying all the information so much.
We have our new little chicks and are just thrilled.
I have a question about nighttime heat.

I am using a 100watt bulb in a metal clamp lamp over one corner of their box. They move about normally, adjusting their temp as expected. I regularly adjust the lamps height over the box according to their behaviors. So, this all seems fine for daytime- but its just occuring to me- how will I keep them warm at night?

What do other people do for night-time heat? A special bulb? Should they be under the bright 100 watt light all night long?

Sorry if this is a dumb question. Everything I read just talks about 95 degrees, decrease by 5 degrees a week, etc,etc, but I've yet to see anything that mentions specifics on warmth overnight.

For now, I am just leaving their bright 100watt bulb on all night- but I am concerned that they have no low-light nighttime experiences(if they need it) at this point.


sorry so long- thanks for reading!!

Mary

 

thanks to you both for your replies!