I Am A67 Year Old Worker In A Retail Store

I am a67 year old worker in a retail store selling material and craft items and supplies.. Store temp is set by the home office in Ohio and we are in Western Mt. I work cutting fabrics and helping customers find what they need. I have noticed that it is extremely hot in my area as confirmed by coworkers. But when we are very busy and physically active I begin to feel extremely warm and at times not only nauseated but almost not as clear thinking as I feel Normally. Is it possible to get physically ill from too much heat and no ventilation?