Heart Rate in cold Weather

The temperature has been around 8° degrees that last few morning but today it was 1.0°.  Before beginning my run I walk for 5 minutes as a warm-up and usually I  manage to just get into Zone 1 ( 50-60%).

This morning however I had only walked a few paces and I was already at the far end of Zone 1 heading for Zone 2. 

Does the cold weather affect the heart rate by increasing it in order to try and stay warm ?.  I had a good sleep and everything was normal except for the elevated heart rate.  My run was fine but I was 10bpm over my average and yet I felt as though I was breathing running quite easily.

Could be all sorts of things. Last week I had a late night and a few drinks and thought it was that that was causing it to beep at me after about 100 metres. 24hrs later I had a heavy cold and that was more likely the reason. I was run down and did not know

I have had some days where I get 50m down the road and its beeping at me, the next day I might do a mile.