This question is not about the meaning of and the difference between the words insulation and isolation, it has been already answered here: What's the difference between "insulated" and "isolated"? and here Difference between "isolated" and "insulated".
In other languages these two concepts are usually expressed by one single word.
They have practically the same etymology:
"standing detached from others of its kind," 1740, a rendering into English of French isolé "isolated" (17c.), from Italian isolato, from Latin insulatus "made into an island", from insula "island" (see island (n.)). English at first used the French word (isole, also isole'd, c. 1750), then after isolate (v.) became an English word, isolated became its past participle.
1530s, "make into an island," from Late Latin insulatus "made like an island", from insula "island" (see isle). Sense of "place in an isolated situation, cause (someone or something) to be detached from surroundings" is from 1785. Electrical/chemical sense of "block from electricity or heat" (by interposition of a non-conductor) is from 1742. Related: Insulated; insulating.
Do I understand properly that the word was imported into English twice, once directly from Latin (1530), and then again via French (1740)? Then it is funny that the notion which sounds more modern is carried by the older word. Or was it one word which somehow "split" into two?