Our products are heat stable. We do have a "Avoid excessive heat, light and moisture on the bottle", this is put on there so it is not stored in this condition for an extended period of time as it can reduce the shelf life of the product.
As long as your order was only exposed for a short period of time, these are still safe to use and will be just as effective. This warning is more for products that have been in these conditions for a prolonged period of time.