One time I biked to work (~5 miles) on a summer day (80+ F) wearing nothing but underpants and a PPE suit from childrens' hospital Boston. The only thing exposed to air was my face.

When I got to work, I was swimming in my own sweat. I remember taking it off and draining buckets of sweat out of the 'sock parts'.

If this thing is air tight, I expect it would work about the same. That little blower wont be enough to cool you down on a warm day and you will be enjoying a sweat bath.