Here's what I wrote:

Subject: I have a closet full of Carhartt. Will never buy again if you fire your unvaccinated employees.

Comments:

All vaccines available in the USA are offered under an Emergency Use Authorization from the FDA, so they aren't approved, and the long term effects are at this point unknown.

A big percentage of your customers are refusing to get vaccinated despite all the pressure being placed on them by companies like yours to chose between their jobs or the risk of an unknown.

There will be a big backlash in your business if you go ahead with this. We are a big part of your customer base, not a small one. You should cancel this policy or delay until the safety and effectiveness of the vaccines is better understood. At this time there is no crisis that would be solved by firing your unvaccinated employees.