Scarlets Cut Flower Patch 2022/23/24

Ladies, FEW and Scarlet, do these flower seeds need continued bottom heat after germination and pricking out at this time of year?

Everything I've sown so far are "hardy annuals". I do have a heat mat in the greenhouse - so somethings are on that but mostly I just cover over with lids if it's forecast very cold. I take out of the prop the minute I see germination.