Hey are you still breathing?

From the Birmingham Sunday Mercury (7th Jan 2001)
Worker dead at desk for 5 days

Bosses of a publishing firm are trying to work out why no one
noticed that one of their employees had been sitting dead at
his desk for FIVE DAYS before anyone asked if he was feeling
okay. George Turklebaum, 51, who had been employed as a
proof-reader at a New York firm for 30 years, had a heart attack
in the open-plan office he shared with 23 other workers. He
quietly passed away on Monday, but nobody noticed until
Saturday morning when an office cleaner asked why he was
still working during the weekend. His boss Elliot Wachiaski
said "George was always the first guy in each morning and the
last to leave at night, so no one found it unusual that he was in
the same position all that time and didn't say anything. He was
always absorbed in his work and kept much to himself. "A post
mortem examination revealed that he had been dead for five
days after suffering a coronary. Ironically, George was
proofreading manuscripts of medical textbooks when he died.

You may want to give your co-workers a nudge or kick
occasionally.