10 to 15 per cent of us are sleep deprived already and losing an hour's sleep because of the clocks moving ahead doesn't help.
A study in the New England Journal of Medicine in 2008 found the number of heart attacks went up significantly in the three days after the shift to daylight time. Other studies have found the number of traffic and workplace accidents also go up in the first week after the change.
Dr. Adam Moscovitch of the Sleep and Fatigue Institute in Toronto warns the effect of that one hour change can last an entire week.
