Today's forecasted heat index – 105 degrees to 110 degrees – is high enough that some some outdoor workers could become seriously ill if they and their employers don't take precautions, according to guidelines developed by the Occupational Safety and Health Administration.
The advice applies to anyone spending time outside – including those at the 2013 U.S. Senior Open.
The heat advisory for the Omaha area runs from noon to 7 p.m. The risk should be short-lived though, because a cool front is expected to move through, dropping temperatures back into the 80s on Wednesday.
OSHA and the National Weather Service have begun working together to better publicize the threat that heat poses to outdoor workers.
As a result, today's National Weather Service heat advisory singles out outdoor workers for caution: "There will be an increased threat for heat exhaustion or heat stroke."
An advisory signals uncomfortable humidity that would only become life-threatening if precautions aren't taken. The more serious, heat warning means excessive, life-threatening heat is likely.
Today's risk is compounded because it's one of the first dangerously hot, humid days of the summer. According to OSHA, that's when workers are most vulnerable, because they have not had time to become acclimated. Among those most at risk are seasonal or temporary workers.
Humid days like today also are unhealthy because the body can't sweat efficiently -- sweating is how the body keeps itself cool.
OSHA considers a heat index of 103 degreest to 115 degrees to pose a high risk to outdoor workers, while an index of 115 degrees or higher is considered "very high" and requries aggressive actions by employers to protect workers.
The agency also notes that its guidelines understate the risk to those who work continuously in the sun. That's because the National Weather Service heat indices are based on shady areas and a breeze. Working in full sun could raise the heat index by 15 degrees, according to OSHA.
In general, OSHA recommends that employers:
• Provide workers plenty of water.
• Allow additional breaks – in shade or air conditioning.
• Use a buddy system. Someone suffering from a heat-related illness can become confused and not realize that his/her health is deteriorating.
• Designate a knowledgeable person at each work site to assure that frequent breaks are taken and workers are drinking water.
• Reschedule work to cooler parts of the day, ease workloads and increase breaks during hottest part of the day.
Here are OSHA's water recommendations, based on this afternoon's heat index:
• Sip water every 15 to 20 minutes, consuming about 4 cups of water an hour.
• Because drinking too much water can be fatal, consume no more than six cups of water an hour, or 12 quarts a day, under most circumstances.
• Water should be palatable and cool.
• Avoid drinking caffeinated or high sugar drinks such as soda.
• Be especially careful if individuals work in full sun continuously.
The agency also recommends people wear hats and apply sunscreen. Here are some interesting tips from OSHA: put cold packs in pockets, wear reflective clothing or dampen clothes with water.
As the cool front moves in, the storm chances increase late this afternoon and evening. The most likely time for storms in the Omaha area is between 7 p.m. and 1 a.m. Those areas that don't get doused by a storm are unlikely to see much rain, according to the weather service.
The rest of the week's forecast:
• Wednesday: Sunny, highs in the low 80s, light north wind.
• Thursday: Mostly sunny, highs in mid-80s, light winds from the southeast.
• Friday: Mostly sunny, highs in upper 80s
. • Saturday and Sunday: Highs around 90 degrees; a chance of storms Sunday.