Having experienced similar issues later found to be sensitivity to certain chemicals, it appears that many people with "EHS" actually are unusually sensitive to the fumes given off by hot plastics.
Especially new hot plastic, ie from a router, laptop etc.
The interesting thing about it is that if you have a mask which blocks VOCs or have really good ventilation in the room, the problem goes away.
I now have to regulate my exposure to said fumes, even to the extent that a photocopier makes me feel dizzy if in a confined space. This could be connected to asthma as there are related allergies including strangely enough to bananas and some citrus fruits (!)