At this price, even if the waterproof effect of the coat is good, the air permeability is not good, because the laminated fabric can not achieve the waterproof and air permeability effect. This can't be helped, the cost is there, and the cost of 350 waterproof and breathable fabrics is similar. I estimate that your waterproof glue is similar to the plastic film pressed on the fabric. It is waterproof, but can it breathe? In order to lower the price, many domestic low-end jackets use very cheap fabrics. I don't think such clothes are called jackets.
See if there is a zipper under your arm, and if there is one, open it, so that you can get some air properly. If not, it only means that this dress is a raincoat. Except for rainy days, it is usually put in the closet. Turn around and buy a better one. Be sure to look at the fabric before buying. Outdoor things, it seems that the higher the cost performance, the less suitable for outdoor sports.
Alas, domestic brands are so gullible and short-sighted.