We had an outdoor patio show on Saturday, temperature was 18 degrees C (64 F) or so when we started but got down to around 9 degrees (48F) by the end of last set. You could see our sax player's breath. My arthritic old hands were all but locked up. We have a private party booked next weekend, on a flat bed stage w/ no cover - anticipating a low of 6C (42F) by midnight. Any tips for getting through this?