Burning release heat, for example.
The burning of a fuel transforms chemical energy into heat and light energy.
Chemical energy usually transforms to heat energy. Heat energy causes expansion of materials, producing kinetic energy. In some cases, chemical energy may cause a direct expansion of a material, producing movement (kinetic energy) but the heat stage is usually present. Gun powder, dynamite and gasoline all are chemical-heat-mechanical.
A heater or furnace is a device that transforms stored chemical energy, such as natural gas or propane, into heat energy through combustion. This heat energy is then used to warm up a space or heat water for various purposes.
The energy transforms from electrical energy to heat energy in an electric blanket. When the electric current flows through the wires in the blanket, resistance in the wires produces heat, which warms the blanket.
Burning a candle or causing oxidation of a chemical. You can also create heat by placing sodium metal in water (caution, this is dangerous).
The battery chemical energy transforms into electric energy that is demonstrated as light.
Conservation of heat
I think you mean to understand that chemical energy is converted to heat and mechanical energy.
A flashlight transforms electrical energy into light energy and a small amount of heat energy. The electrical energy powers the light bulb, which then emits light energy to illuminate its surroundings.
Food energy is used for heat and motive energy (muscle contraction).
Chemical energy transforms to thermal energy when baking a cake.
The transformations that you describe are quite common. Fire does this. Chemical energy in (for example) wood, transforms into heat when you burn the wood, and when you get enough heat, you will then also get light; in a fire, you get a glowing, very hot gas called plasma.