Please tell Denise and make an appointment with your local GP. Just to be safe!
I know your weather doesn't remotely resemble ours (hot and humid) at the moment, but have you been drinking enough water? I've had issues with dehydration several times, and nausea followed by fainting are two of my common symptoms.
I know, I know. I think too much sometimes!
We just want you to feel good and be healthy!