I have solved the problem of wanting to sleep under the covers. Point your fan under your bed. this only works if you have that cloth thing that would prevent most air from escaping. the air will go up through the mattress! it cools you even when you have a blanket!!!!

also if it gets too cold, put a blanket down under you, that makes it quite comfy
also make sure the intake of the fan is not blocked or else it wont work.