Does the application of heat to a substance always produce a chemical change?

Answer;

No, sometimes it just causes a physical change, such as ice melting to water.

Explanation;

-The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.

Heating a substance may cause a physical change or a chemical change.  For example melting ice to water, involves supplying heat to change ice into water which is a chemical change.

-On the other hand, an example of decomposition reactions are chemical reactions which involves supplying heat to a substance; for example decomposing copper (II) nitrate which yields, copper (ii) oxide, nitrogen (iv) oxide and oxygen gas, is chemical reaction.

it's filtration, but this is an assumption so my apologies if i got this