I doubt that I would ever call this a 'thermal' top. I bought it because the winter is coming and I need some cooler-weather clothing. This does not qualify. The fabric is so thin that I doubt any insulation will be added at all. I got the teal-coloured one and at least it's not see-through. The colour is nice and the fit is flattering and true-to size. Honestly, I would probably like this shirt a whole lot more if there was more of summer left to wear it.