I had that once and it turned out to be a severe allergic reaction. Definitely go ask a licensed medical professional about this.

Get checked out by your doctor ASAP.

I grew up in Mississippi before my parents had air conditioning. And I am an engineer accustomed to using fans for electronic cooling. Here is what I can tell you: … (1) When it’s hotter outside than inside such as from noon to 7 PM keep the windows shut. You can use a fan inside to help you feel somewhat cooler, though… (2) Use maximum airflow from inside to outside and back out again to cool you when it’s cooler outside. The air needs a path in and a path out. For example a fan in one window blowing in and a window on the other side of the room for the air to blow out. Make sure to take advantage of the wind direction - don’t try to fight the wind with a fan, let it boost the natural wind direction… (3) When it’s cool outside at night use as much ventilation as you can to cool down your home or room since you are going to be counting on using that stored coolness during the heat of the day… By the way, as I write this my air conditioning has broken down and it will be a couple of days until the repairman can come. I am using this and it works. It’s not like AC but it is better than nothing… Finally, keep the sun out as much as possible because it adds to the heat. And thin cotton clothing (like a T-shirt) is cooler feeling than artificial fibers like polyester because it wicks sweat from your body and that helps to cool you.

If it's really hot outside, opening windows generally makes it worse, since you're letting the hot air in. Better to only air out when it's cooler out, towards the evening/night. Though, if this was during the eening/night, my apologies - I guess you're just SOL then. Best you can do then is put a bowl filled with water and ice in front of your fan, I guess.

It can also be a sign that your landlords changed your windows for some shitty panels with Dollar Store handles and a 4-in maximum opening, and all tenants who tried to open their windows further got them banging on the walls nearby at the slightest gust of wind. Take cool showers, moisten your forehead and neck with a damp cloth, and drink a lot of fluids.

I'm a 51 year old woman. This is normal every 20 minutes.