Sure sign of Spring?

At work, everyone are dropping like flies from sickness. We had at least 6 guys calling in sick on Friday, and my team had to guard the fort with just the 3 of us. I'm still healthy as heck though, which I attribute to my daily practice of Baji and Taiji. I don't remember ever seeing so many people getting sick in one group before, so I guess it's the flu season now. Hence only next logical conclusion is, Spring is here!. The temperature has shot up to above zero recently, the forecast of this weeks has spring written all over it as well. I'm still cautious though, Canadian winter always dies hard.