Methods of treating, reducing, and/or preventing heat stress are provided. For example, provided is a method of treating or preventing heat stress in a subject comprising selecting a subject in need of heat stress treatment or prevention and administering an effective amount of one or more of astaxanthin and milk casein hydrolysate, or a derivative thereof to the subject. Also provided are methods of reducing the effects of a fever in a subject comprising administering an effective amount of one or more of astaxanthin, chromium and milk casein hydrolysate, or a derivative thereof, to the subject. Also provided are pharmaceutical compositions, comprising astaxanthin and one or more of chromium or milk casein hydrolysate.
