When I was researching the book Toxic Electricity, I would see biological reactions for up to a week afterwards. They are typically strong in the first day or two after the electromagnetic field (EMF) exposures and tail off as the week goes on. I would feel fine during the EMF exposures and start seeing weird health effects usually during sleep that night. Extended time around high voltage power lines & power poles were the worst for provoking reactions, followed by wifi and transmitting utility meters.
There were three people in my home and I was the only one showing Electromagnetic Hypersensitivity and reactivity to the radio frequency transmitting utility meters. For these reasons I did not shield my home and took the route of adapting my body to the toxic electromagnetic environment.
It has been known for many years that a subset of the population cannot tolerate the radiation emitted by transmitting utility meters and sickness results in these people.