Where were you sat? I think the 763 has difficulty maintaining the same temperature throughout the whole cabin.

For example, seat 26A is always positively Baltic, seriously shiver-worthy. However when walking around the cabin I have noticed it is much warmer in other parts. Even two rows back. They probably have to keep the heat up from stopping people in 26A from getting hypothermia.

I think they know about it too. I have often used the low temperature on a MAD LIM flight as my excuse for having too many coats on my LIM BOG flight.