what IS this?

don't know where this fits, soi'm posting it in a few places. any help will be appreciated:

when i was a child thru young adult, i would suddenly have this sensation while asleep or i guess i wouldn't actually BE asleep, where it felt like my whole body was swelling up - like elephantitis. i definitely remember my tongue swelling but i would be somewhat asleep. also there was always a radiator in the dream also which i have no idea what the connection was. i was never tied to a radiator or anything like that. i couldn't stop it from happening once it began.

i couldn't "shake" it, i would have to try to wake myself up and stay up for awhile to make sure it didn't come back when i fell asleep. this sensation happened quite often but i have never heard/read of anything like it

any ideas?