1 Having high or low cholesterol does not exclude a person from donating blood. 2  Potential blood donors may be temporarily prevented from donating if they have a low level of iron (hematocrit) in their blood.
Headline Clickable. To keep food warm without overcooking, set your oven to the lowest temperature (which is probably 200 degrees F) and cover the food with foil.eadline Clickable. To keep food warm without overcooking, set your oven to the lowest temperature (which is probably 200 degrees F) and cover the food with foil.
Infrared radiation, especially at close range, has a tendency to char things (which is great when you are trying to cook steaks), while hot air does not have that tendency (which is great for cakes). In a normal kitchen oven, what most people are interested in is baking things like cakes or biscuits. So if you are baking a cake and the directions say, Bake at 350 degrees F for 20 minutes, then ideally you would place the cake in a box (an oven) that contains still air at a constant temperature of 350 degrees F.