Delicate subject! Air sickness

I have travelled extensively by plane for more years than I would want to admit to[:I]
Last year returning from Mexico I parted company with my dinner (the politest way I can think to phrase this) about an hour before landing. This is the first time I have ever been ill on a plane, didn't last for long and came on very suddenly, at the same time the cabin appeared to get very hot. No turbulance, in fact I always like a bit of turbulance to remind me I'm actually flying!
Several trips since, including long haul to LAX/back from SFO, with no problems.
Then this year, with the same carrier but from Cuba, sick again about an hour from landing in similar circumstances. Had eaten minimally, and didn't drink anything after the meal service. I have never had a problem with motion sickness (including the effects of turbulance) so what's going on? Might it be something to do with sudden drop in altitude and why would this be different with this carrier?[:I]
Any insights gratefully received.
Regards
Pat
Last year returning from Mexico I parted company with my dinner (the politest way I can think to phrase this) about an hour before landing. This is the first time I have ever been ill on a plane, didn't last for long and came on very suddenly, at the same time the cabin appeared to get very hot. No turbulance, in fact I always like a bit of turbulance to remind me I'm actually flying!
Several trips since, including long haul to LAX/back from SFO, with no problems.
Then this year, with the same carrier but from Cuba, sick again about an hour from landing in similar circumstances. Had eaten minimally, and didn't drink anything after the meal service. I have never had a problem with motion sickness (including the effects of turbulance) so what's going on? Might it be something to do with sudden drop in altitude and why would this be different with this carrier?[:I]
Any insights gratefully received.
Regards
Pat