A package delivery driver in Fairburn, Georgia, started her first day on an unremarkable 78°F morning and never finished her route. She became dizzy, developed a severe migraine, and passed out in her delivery van. EMS responded.

If your organization employs delivery drivers, warehouse workers, or anyone in non-climate-controlled environments, heat illness is a risk you should be actively managing. And, if your workforce is offsite, the challenge is compounded. "For people working out by themselves, they really have to know their body and the response plan," says Kelsey Keith, Director of Loss Control at Kinetic.
This post covers what HR directors and operations leaders need to know to build a heat illness prevention program that protects workers before the temperature climbs.
Heat illness exists on a spectrum. Where a worker sits on that spectrum determines whether you manage on-site or call 911.
"Once you hit heat stroke, it can progress very quickly," says Kelsey Keith, Director of Loss Control at Kinetic. "The person can lose consciousness. It's really important that they are treated by medical professionals before they get to this stage."
Learn about these and other heat-related illnesses and first aid from OSHA.
A Houston claim came in at 84°F: a worker with heart palpitations who called 911 from a customer's doorstep. The Georgia case above was 78°F. Both temperatures sound manageable. Neither was.
The right metric is the heat index, not temperature. The heat index combines temperature and relative humidity to reflect what the body actually experiences. An 80°F day with high humidity can produce a heat index above 90°F, well into the range where heat exhaustion risk climbs significantly.
"You can't look at temperature alone," Keith says. "You have to look at the heat index is for the day."
Once the heat index is forecast to reach 91°F, active monitoring should begin. At 80°F in the forecast, start prepping employees.
According to OSHA’s heat illness prevention framework, reinforced by Keith, an effective heat program comes back to three fundamentals: water, rest, and shade.
A complete program also includes a written heat plan, supervisor training, and a clear emergency response chain. OSHA's Heat Illness Prevention fact sheet and Heat Exposure webpage provide more details.
Supervised environments let coworkers and supervisors monitor each other. Independent workers don't have that.
When the Houston driver began feeling faint, there was no supervisor on-site. She went to a customer's door and asked that person to call 911.
OSHA acknowledges that on-site monitoring isn't always feasible in industries with distributed workforces such as package delivery. In those cases, it recommends a trained central contact who can monitor heat conditions remotely and maintain communication with workers in the field.
For independent workers, the employer's responsibility shifts to preparation and self-monitoring. Workers need to know the symptoms, know they can stop without penalty, and know that calling for help, from wherever they are, is expected.
"Making sure they know they can tell themselves to take a break," Keith says. "Especially if they're working independently, drivers have to know that they're able to make the call if they feel like they are getting overheated."
Autonomy built explicitly into your heat program is a loss prevention strategy.
One of the most consistent findings in occupational heat data: over 70 percent of heat-related deaths occur during a worker's first week.
The body requires time to acclimatize. OSHA recommends starting new workers at 20% of expected heat exposure on day one, increasing by no more than 20% per day, with full acclimatization taking up to 14 days. For any hire starting in warm months, heat illness awareness belongs in onboarding explicitly, not assumed.
As average temperatures continue to rise, so does exposure. According to NCCI research on adverse weather and workers' compensation frequency, injury rates begin climbing just a few degrees above baseline, reach 5% above normal in the low 80s, and hit 10% above normal when temperatures exceed 100°F.
Construction sees nearly double that warm-weather impact.
Transportation and Warehousing show significant claim increases in both hot and cold conditions.
On the hottest days, contact injuries (workplace accidents caused by direct physical impact with an object, equipment, or another person) run more than 10% above baseline.
Keith's guidance is direct: do not wait until peak summer. Prioritize three things: a documented water, rest, and shade plan; a heat index trigger set before symptoms appear; and heat illness coverage in onboarding for warm-month hires. Those three actions, even informally documented, close the most common gaps.
Tornadoes and blizzards register as emergencies. Heat does not, at least not until it is too late. "Heat is one of those things that could impact every single person," Keith observes. "Everyone has felt hot days. But there's a difference between going inside after 10 minutes and being required to stay outside for your entire eight-hour shift."
That normalization is the real risk. Workers and employers underestimate heat because they have experienced it before and been fine. A well-built prevention program closes that gap by making the right behaviors automatic.
Workers' compensation claims for heat illness are largely preventable. The interventions are not expensive. What they require is a plan built before the hot days arrive.
For more on protecting workers in high-risk moments, read more on dog bite prevention for delivery drivers and preventing winter slips and falls.
Safety talk information is for general guidance only and should not be relied upon for medical advice or legal compliance. Recommendations provided are general in nature; unique circumstances may not warrant or may require additional safety procedures and considerations. Kinetic, its affiliates and employees do not guarantee improved results upon the information contained herein and assume no liability in connection with the information or the provided suggestions. Kinetic does not make any warranty, expressed or implied, that your workplace is safe or complies with all laws, regulations, or standards.