They should be warming occasionally under the heating pad at a week old, but not be staying under it all the time. But be sure they can easily get under it and there's room to stand up as well as lie down while still having contact with the pad. I like a tent shape rater than flat so the chicks...
I'm ashamed to admit I was trying to puzzle out mention of "10 week old" chicks with a photo of chicks that couldn't be more than one week old. Then it dawned on me you meant ten one-week old chicks.
I used to be pretty sharp. Lately, not so much.
Chicks any older than about three days...