Hi santo101979,
The first place I would start is the mattress shopping tutorial here which has all the basic information, steps, and guidelines that you will need to make the best possible choices … and know how and why to avoid the worst ones (either mattresses or stores).
This type of complete misinformation is common in the mainstream industry and it’s quite likely that after you have spent an hour or two reading the tutorial post and the posts it links to that you will know much more meaningful information about mattresses and different materials than they do. They are just trying to “sell you” a story so that they can make a sale.
The better options and possibilities I’m aware of in the Chicago area are listed in posts #2 and #4 here but I would start with My Green Mattress / Quality Sleep who sell latex mattresses, will give you more accurate information, and will “educate you” much more than “sell you”. They are also one of the invited manufacturing members here which means that I think very highly of them and compete well with the best in the industry in terms of their quality, value, and service.
Phoenix