Working in hot environments for long periods can lead to heat stress, heat exhaustion, heat syncope, and the most severe, heat stroke. Symptoms include dehydration, leg cramps, fainting, and increased body temperature. To prevent these, one should avoid direct heat/sun exposure, stay hydrated by drinking water regularly, rest in the shade when possible, and seek help immediately if symptoms occur. For heat stroke victims, it is important to cool the body by removing clothes, applying water, using a fan, and seeking immediate medical attention.