Could you help me please? Easy English question. :)?

[gary b]

You've created a dangling participle.

In casual speech, that's an error that's likely to go unnoticed. Your meaning is clear. The lack of referent for the subject is not obvious. It isn't easy to notice that this use of "it" shouldn't be modified by "being inside". I'm really nitpicking here.

There are two possibilities that I'd like you to consider. The first is to drop the participle entirely. The second is to have a subject which works with the participle.

- Even inside, it's still cold.

The word "inside" can act as an adjective or an adverb. Regardless of whether you consider it to modify the verb or the complement, the meaning of this sentence remains pretty much the same.

- Even being inside, I'm still cold.

A subject like "I" or "we" can easily be modified by a phrase like "being inside". It has a clear referent which can sensibly have such a state.