Abstract We show that a thermal relic which decouples from the standard model (SM) plasma while relativistic can be a viable dark matter (DM) candidate. if the decoupling is followed by a period of entropy dilution that heats up the SM. but not the dark sector. Such diluted hot relics can be as light as few keV. https://www.pyrodresoners.shop/product-category/3d-tpu-parts/