Hopefully wearing appropriate riding gear for Thailand? ... not UK Winterized gear? Good HOT weather gear exists. No need for flip flops and shorts. Many Farang end up in emergency there. Nasty. (seen it in person!)

We see a few RTW travelers come through California & run into them in Mexico wearing gear suited for N. EU and UK climes. Thick, heavy WP jackets/ pants, don't vent well. Good down to below freezing but over 27C (80F) they are miserable.

ALL W R O N G for Summer or the Tropical South! Heat stroke is real. Dehydration, exhaustion ... misery.

Why not do what racers do? I'm sure our Oz brothers know about this too.
In my racing days I rode a few Enduros in Hot weather, did Desert racing in the Mojave too.

You had to have protection ... but needed to stay cool. Used those tips from back then in current hot weather riding kit. Not perfect, but much better than flip/flops and shorts.

Part of this kit includes mesh dirt bike riding pants. Very strong, yet flow a TON of air, even moving 15 mph. If it turns cold ... you MUST stop, change, or ...slip rain pants OVER the dirt riding pants for warmth.

I always wear my independent KNEE and HIP guard armor under the dirt pants.

Up top it's a compromise ... risky.
No armored riding jacket (w/built in back protector). But there are now so many GOOD Fully armored FULL mesh jackets out there that work very well in heat and humidity. Light colors helps too. That is my recommendation ... perfect for Thailand.

But when going without Mesh jacket I wear long sleeved dirt bike Jersey but with independent Elbow/forearm strap-on guards. So ... NO back protector. But one could wear one. ... or get a Mesh jacket ... many for under $100 USD.

ALWAYS wear Boots & Gloves ... no matter temps. (unless just popping out for dinner, short distance) Almost always wear my Flip-Up helmet (UP position in slow going) but ride with it down at speed.
In SUPER-HOT heat, it's cooler to run shield DOWN. (IE: Death Valley in 118F/47C)

Toughest heat, IMO, is places like Asia/India where you've got 95F/35C with 90% humidity. Very tough, no matter what you wear. After time and acclimation, you may be able to ZEN your way through this ... like the locals do. Takes practice. Most fight it ... and end up hating life and whinging.

If you can avoid super hot weather, do it. If not, try to ride smart. Ride EARLY AM or at night. Knock off early, get drunk! Not much fun riding a bike, stuck in traffic, going 10 mph, sat at traffic lights in mid day Sun.