Had wisdom teeth removed, hot wrags ?

I had my wisdom teeth removed 3 days ago via surgery.My dentist told me to use hot wrags to keep the swelling down. They told me that the wrags should be too hot to wring the water from. I've been microwaving them for about 35 seconds after wetting them. The problem is that I have to get up every 2 or 3 minutes to mic the wrags again. Is there any way that I can keep them hot for longer? Thank you!