[shvcko99]

My first question is: Is the term "heat" usually the same as or implying "high temperature"?

Does heat (or high temperature) almost always facilitate chemical reaction?

Is there any chemical reaction you can think of will proceed better or even only start at low or very low temperature?

[Borek]

My first question is: Is the term "heat" usually the same as or implying "high temperature"?

Yes (although these are two different concepts).

Does heat (or high temperature) almost always facilitate chemical reaction?

The higher the temperature, the faster the reactions: https://en.wikipedia.org/wiki/Arrhenius_equation

Is there any chemical reaction you can think of will proceed better or even only start at low or very low temperature?

Sometimes running reactions at low temperatures helps avoid interfering reactions, thus facilitating making of the desired product.

[shvcko99]

My first question is: Is the term "heat" usually the same as or implying "high temperature"?

Yes (although these are two different concepts).

Does heat (or high temperature) almost always facilitate chemical reaction?

The higher the temperature, the faster the reactions: https://en.wikipedia.org/wiki/Arrhenius_equation

Is there any chemical reaction you can think of will proceed better or even only start at low or very low temperature?

Sometimes running reactions at low temperatures helps avoid interfering reactions, thus facilitating making of the desired product.

I have some processed foods and drinks which are not supposed to be stored or served frozen but I foolishly kept them in the freezer section and they have become kind of solid, I am wondering if there could be any unexpected reaction that causes problem to those food because there are many different addictive  or regulators in those food or if I have over thought for something that doesn't exist. Thanks again for answer

[Corribus]

There are some rare cases where the rate of product formation decreases with temperature, but you probably don't need to worry about them. In chemistry there are always exceptions to every rule.

Regarding your freezer question, it depends on what you mean by "problem". In most cases there won't be a safety issue but quality of the product can definitely change due to certain physical processes that can occur during freezing (precipitation, crystallization, evaporation). These processes can affect texture, color, and water content. "Freezer burn" is one you've probably heard of. Also if you've ever frozen and thawed a banana, you know what I mean.

[Borek]

Chemical reactions in the food are between last things to care about. What typically matters is a microbial decomposition.

[shvcko99]

Chemical reactions in the food are between last things to care about. What typically matters is a microbial decomposition.

But shouldn't most decomposition also slow down under ice point?

On the other hand, can I safely assume that most processed food with a mixture of different chemicals are not changed at all when they are repeatedly brought below ice point and above room temperature or a bit higher (even if they are not supposed to be frozen at all)?

For example, are kind of man-made chemicals commonly used in foods and drinks e.g. flavorings, stabilizer, antioxidant generally inert to each other among wide range of temperatures?

[Borek]

For example, are kind of man-made chemicals commonly used in foods and drinks e.g. flavorings, stabilizer, antioxidant generally inert to each other among wide range of temperatures?

This is getting boring - you were told many times and by different people that this "artificial chemistry" line of thinking doesn't make sense, yet here we are again.