Hi Tony, I to, had the Nissen on April 30th.
After I was brought to my hospital room, I had a hot flash.
I became very hot, sweaty and uncomfortable. I almost felt like I was going to panic, and was telling my husband to immediately adjust the thermostat in the room.
Since I have been home, I have had this happen a couple more times.
It seems like each time, I was having some pain and/or discomfort in my abdomen.
If it happens again, I will try to see if coincides with taking the pain meds.
Hope you have a good recovery.