Hello Ms tas17,
By "Chest flushing", do you mean that the skin over the chest region is warm, and uncomfortably swollen?
Your symptoms of tightness of breathing and raised pulse are more medically significant, as you are re-inducted to high altitude. All forms of "mountain sickness" are more common among those who get exposed to high altitude a second time. Please don't disregard them. If you are breathing hard, even while you are resting, please get supplemental oxygen
, medical help
and come down to lower altitudes at the earliest.
Skin involvement is not likely to be a typical effect of high altitude. If you never had the flushing at sea-level ever before, it could be an effect of altitude, not yet recognized.
Hope you enjoy the serenity of Colombian mountains in comfort,
With warm regards