Hello. I need to find a fabric to cover/encapsulate myself along with my NIR pocket sauna so that the heat does not escape much and the heating is more effective.

However, I have no idea what type of fabric I should buy and from where to buy it. I saw that saunaspace.com sells sanforized cotton fabric along with wooden poles but it is super expensive. Are there any alternatives? Some kind of a fabric that is at a good price and does notemit harmful chemicals when heated is what I am looking for.

Do you use such a covering fabric or do you just stay/stand/lay close to the NIR bulbs?