Of course, not every weak hit is a cold-weather issue. If your device still performs poorly after warming up, you might be dealing with something else:

• Battery is actually low: Cold can reduce battery efficiency, but if it's genuinely drained, warming won't bring it back.
• Coil is burnt: If you've been vaping through a dry wick (which happens faster in cold weather), the coil can get scorched. That burnt taste won't go away with heat.
• Device is defective: Sometimes you get a dud. If warming and proper draw technique don't help, it might just be a faulty unit.

Also, note that extreme cold can cause the battery to temporarily underperform. Once the device warms to room temperature, it should work normally. If not, it's time to replace it.