My response is based more on a best guess than expensive experience using what I am about to recommend in summer [because pre-covid I used other masks most of the time, as discussed previously].
One option would be the traditional earloop pleated medical type masks like you used to be able to buy at a pharmacy OTC. They were all sold out but now seem to be coming back in stock, though not necessarily in the brands you are used to. See my previous post about those. They are lightweight and *ideally* you would just dispose of one and switch it out for a new one if it became too moist.
Another option is a mask (or a gaiter or other style of face covering if allowed in your jurisdiction) using a one of the technical sun protective fabrics that are intended to be lightweight and cooling and wicking. Yes, such things exist. People who are sun sensitive or want to wear UPF clothing as an alternative or complement to sunscreen wear them, as do people like fishermen and others who are in high sun environments where sunscreen just is not enough.
A little about two of the sun protective options based on my personal experience with the fabrics and companies for sun protective clothing reasons with light face covering. Note that these are two I am familiar with, have used for many years, and recommend, but there are other companies out there who make quality products, so these are just examples.
The first is Eclipse:
https://eclipseglove.com/ Eclipse makes AMAZING sun protective gloves and sleeves and this is what I first started with of their products. I often wear them when driving, and **I wear them all day long during my WDW and
DCL trips**. I can attest that whatever part of my arm is covered by the eclipse sleeve or glove and exposed to the sun is MUCH COOLER than any bare skin, both in "how it feels" as well a physical temp if you touch your hand to it [the proverbial hand to the forehead test only this is the hand to the arm or hand test]. It is amazing and wonderful and did I mention amazing ? It also wicks the sweat off quite effectively without the fabric getting wet. If you read the technical info about the fabric they use on their website, this is exactly how the fabric is supposed to work.
In addition to their sleeves/gloves, they have a fairly new range of clothing, and I have some pieces from that. They also have a neck gaiter, and I have one of those. I quite like the gaiter and have put it through a few uses, including snorkeling with it at Castaway Cay [I have a full face snorkeling mask, and I wore it as basically a hood around my head and tucked up against all around the mask, giving me excellent sun protection for my face and head and neck, which went along with my sun protective long sleeve rash guard and swim tights and socks - as you can see, I avoid the sun and use extensive sun protective clothing]. The gaiter can be worn in the style of a face covering and for my head at least it stays up well == they also have an adjustable version. Same material as the sleeves/gloves, so expect the same properties. I have worn it in FL all day as a neck gaiter providing neck protection and it was quite comfortable.
Next up is Coolibar:
https://www.coolibar.com/ . Coolibar has an extensive range of sun protective clothing, from clothing to swimsuits to coverups to hats etc etc etc. I have quite a collection of their stuff, as does my sister, and we have been happy with every piece. They are a mainstay of our wardrobe for our WDW and DCL trips. They have a number of different products they use, each with its own weight and properties.
As an example, I have an earlier version of a hat of theirs that is similar to this one:
https://www.coolibar.com/sun-hats/s...hlorine-resistant-ultra-sport-hat-upf-50.html On one of our trips I wore it for hours at Typhoon Lagoon in a December visit, temp in the 80s. It is wearable, but it does get hot under there. Because of the design, you can shift the fabric a bit and it will vent a bit. But while it is suited for a pool/water environment, you don't need the heaviness of that fabric for a day to day normal non pool environment.
If you search their site you will see they have a range of masks, gaiters, bandanas, and scarves made from a range of fabrics. Their site has good info on the technical qualities of the different fabrics they have.
SW