Heat is transferred from the heat lamp to the hamburgers through radiation. The heat lamp emits infrared radiation, which is absorbed by the surface of the hamburgers, warming them up.
You are changing radiant heat into thermal energy when you set food under a heat lamp to warm it. The heat from the lamp is absorbed by the food, raising its temperature and allowing it to heat up.
blanket and heat lamp (I recommend a blanket)
electromagnetic waves will transfer thermal energy from the lamp to the fries
electromagnetic waves will transfer thermal energy from the lamp to the fries
Fooding warming trays keep food warm by applying heat to a small amount of water in a tray underneath the food tray. The tray containing the water is heated either by electricity or with small alcohol gel candles. The heat and steam radiated up from the water and tray holding the water keeps the food warm.
Feed enough food to keep it fed, put a heat lamp in a larger pen or a light bulb in smaller one(for heat). Keep the pen or cage clean and dry.
Food can generally be kept under a heat lamp for about 2 to 4 hours, depending on the type of food and the temperature of the lamp. It's important to ensure that the food stays at a safe temperature of at least 140°F (60°C) to prevent bacterial growth. After this time, food quality may decline, and it may be safer to discard it to avoid foodborne illnesses. Always monitor the food and check for any changes in texture or aroma.
As you know light bulbs give off a good amount of heat, so to keep food under a light will keep the food somewhat warmer. That is why resturants keep plates of food in the "hot line," just a fancy way to say a counter with a lamp over it.
Heat lamps are just infra-red ray emitter. In simple terms they release waves containing energy. As these infra-red waves reaches the food, they transfer into heat energy and thus heating the food. In summary light energy turns into heat energy.
convection
The Lamp goes in your brooder, the eggs go in your incubator. Regards