My Mom Come To Denver From CA A Couple Days

My mom come to Denver from CA a couple days ago. I somehow caught a cold yesterday. today my mom woke up with sore muscles around the boobs, she is dizzy, she says all her upper muscle's are really sore like she did a ton of exercises, also we drove up to a park where she had to stop to catch her breath, this is a task she could normally do. I am struggling to determine is she is catching my cold, has altitude problems, taking some kinda medication that is causing this(she says she is on an antibiotic), or something bigger like a heart problem. right now she up and acting fine, but many times she gets up and gets very dizzy.