I've never heard about
aspirin and heat so I googled it:
"Have you ever exercised in summer heat, felt achy and sore after, and reached for an over-the-counter anti-inflammatory medicine (think aspirin, ibuprofen or naproxsin)?
If so,
watch out. These OTC anti-inflammatories, also called NSAIDs, are affected by your hydration status. If you’re low on water after an intense workout, or say, an afternoon of imbibing in hot summer sun, and you take one, you risk serious health consequences, including heat stroke and kidney failure."
/weather.com/health/news/dangers-ibuprofen-aspirin-and-summer-heat-20130802"
Warning: Aspirin or non-steroidal anti-inflammatory drugs should
not be given to workers to relieve symptoms of heat stress."
www.ehso.emory.edu/content-guidelines/Toolbox/ToolboxTraining_HeatStress.pdfNote that both of these talk about
"heat stress" - which is different than just going out and sitting on your patio when it's hot outside.