When you are working in the heat, you will sweat out water. You will need to drink more than the recommended daily allowance to replace those fluids. If the temperature gets above 103 degrees F., you should drink water every 15-20 minutes. Drink small amounts frequently rather than gulping down huge amounts. If the heat index is between 103-115 degrees F., drink four cups of water per hour. Avoid caffeine which has a dehydrating effect on the body.
As an employer you need to make allowances for working in the heat. Allow your workers to take regular breaks. Provide shaded or air conditioned areas for them to take these breaks. As an employer, you should be monitoring weather conditions when you have workers on the job outdoors. If the forecast is for extreme heat and humidity, you should consider rescheduling the job or rearranging the times of work so that employees are working during the coolest part of the day.
Employers should consider providing their heat exposed workers with water dampened cotton clothing, reflective clothing, and cooling vests with pockets for cold packs. You should also provide plenty of cold water for your employees to drink from over the course of their working day.