Wow sorry to hear that Trond! 5 minutes or even less is plenty until you fully assess the effect of any lamp or lamps(!) The ones I bought are ‘diffuse’ i.e. no bright or focused spot is generated. I have heard though of some people getting lamps with a focused spot design i.e. at say 18″ distance there is a bright white centre spot visible on the skin – this is NOT ideal and IF used one should keep moving around, so that it never dwells on one spot!!! But the key thing is of course to meter any system so that no element of skin ever goes beyond mild erythema (VERY slight pinking in the following 24 hours). A once off in my opinion is not an issue, but this message is important for all to understand. ALWAYS with any light system start very low minutes, gauge and increase only with a guarantee established that max light pinking will be the outcome. Falling asleep is a danger I never thought of – but as it happens I ALWAYS tan standing up, and moving regularly to broadly distribute any focused energy….!