I am a big fan of Renaissance Faires and Festivals – I have a sizeable collection of pirate hats, doublets and billowy shirts and even a pair of thigh-length boots that would make Blackbeard envious. But whenever I go to a Renn Faire at this time of year and see the clientele dressed up in full Tudor formal dress, I worry about their immediate expiration from massive heat stroke.

The daily temperatures during Renaissance Faires (and similar outdoor events) at this time of year in my region (mid-Atlantic U.S.) often go above 30° C (and when you add in the high humidity, the “heat index” can go well over 35° C). You see patrons, however, wearing full Renaissance court costumes from the 16th century, outfits that were (a) worn at a much higher, cooler latitude (b) in the winter, and (c) in a period known as “the Little Ice Age”.
Tree ring data suggest that during the reign of Elizabeth I there was an especially cold period in northern Europe. Famously, throughout the reigns of Henry VIII and his children (Edward VI, Mary I and Elizabeth I), the river Thames froze in winters (it most certainly no longer does so!). In fact, the ice was so thick that it allowed the populace of London to skate, play games, and have winter fairs on the ice. At the height of the Little Ice Age, the temperatures were estimated to be approximately 2° C colder than present, with winter temperatures probably averaging about 5° C during January.

In short, you see patrons at Renaissance Faires wearing costumes in temperatures of 25-35° C that would have been worn when temperatures were 5-10° C.

Now those that are dressed as Vikings (although technically unless they are specifically raiding and pillaging – not recommended at any Renn Faires, even those that allow you to carry weapons – they are not actually “Vikings;” “Norse” or “Dark Age” or “early medieval” would be more correct) might fare a little better, as their costumes are from a time known as the “Medieval Warm Period.” Yet even so, this period, although slightly warmer than the 16th Century, was still cooler than today’s temperatures globally and might be more comparable to modern temperatures in parts of northern Europe. The temperature in July in present-day Oslo averages 18°C, which is a far cry from the hot and humid heat of Washington, DC in mid-summer.

(FYI the norse did not wear horns on their helmets but drinking vast quanties of alcohol …well that is historically correct)

So, if you want to wear a costume at a Renn Faire and, well, not die from heat stroke, wear a costume from a region (and period) that would have had temperatures closer to, and clothing more appropriate for, contemporary temperatures. For example, period costumes from sunny tropical and sub-tropical areas where it was appropriate to wear a lose billowy linen shirt whilst carousing and quaffing vast quantities of alcohol. In short, go pirate! Arrr!