July is coming. It's a time to have fire up the barbecue, hit the beaches and watch the fireworks. It's definitely not a time to be in the hospital. Because fatal medical errors peak in July, an increase that happens to coincide with the annual arrival of new medical residents. That's according to a study in the Journal of General Internal Medicine. Could new docs really be deadly? That's what sociologists at the University of California, San Diego, were wondering. They examined almost a quarter of a million death certificates issued in the U.S. between 1979 and 2006. And they focused on those that showed a mistake with medication as the primary cause of death. They then recorded the month in which the error was made, and whether the incident occurred in a county with teaching hospitals. Turned out that fatal medication errors spiked only in July, which is when new residents hit the wards. And this peak was seen only in regions where training takes place. The results suggest that freshly minted medical residents may need added supervision, or extra lessons in dispensing meds safely. It also suggests that you use extra caution next month with the grill, on the shore and at the fireworks.