Final answer:
The best response is that fetal temperature depends on the mother's temperature, so the fetus may be affected by heat exhaustion.
Step-by-step explanation:
The most accurate response by the nurse to the husband's concern about whether having heat exhaustion will harm the baby would be: "Fetal temperature depends on mom's temperature, so the fetus may be affected." The well-being of the fetus is closely linked to the mother's health. During pregnancy, the mother has to provide a safe and stable environment for the fetus, which includes maintaining a normal body temperature. Excessive heat and dehydration in the mother can lead to increased risks for the fetus, including potential developmental issues and complications. Therefore, it is critical that pregnant women avoid extreme temperatures, remain hydrated, and engage in safe exercise practices.