Although you could leave these on all the time, it would be best to turn it off when not in use for potential health reasons. Even if not accepted by the UK government, other governments (including Germany and Sweden) have accepted for years that they create health problems.

A lot of people (currently about 3% and growing) are being affected by these routers as well as the Wii, as even when the wi-fi part is disabled it is not actually turned off. All that happens is that the device refuses connections (even with mobile phones!). What most people (including those that should!) don't realise is that the device still transmits its carrier signal. Nintendo denied this until I insisted they check. Once they had their senior design staff check they finally agreed, and said they would look at if it could be easily turned off.

They took my claim seriously enough to send 2 VPs to my house to discuss it !

Months later I had a phone call from their European VP of Sales or Marketing who said they would not do anything about it as it would cost too much. This was over 2 years ago and they still haven't done anything, despite revising the design (for cost reasons) several times.

With mobile phones having battery issues you would think they would take every opportunity to minimise battery usage, but they don't.

I always unplug my modem from the BT socket just in case something detrimental comes up the line. This was a habit ithat came from the savagery of lightning strikes in South Africa where I lived for a couple of decades.