I'm thinking of running my group through ToA and I was wondering if there are any rules related to someone wearing armor and the heat.  I can't imagine someone wearing leather armor in the heat and humidity of a jungle much less someone running around in scale or plate mail.

Any information or suggestions.  Is there a way to play it, without killing the party off due to low AC, having them not wear armor.

https://www.dndbeyond.com/compendium/rules/dmg/adventure-environments#Weather

See extreme heat. Characters in medium or heavy armour have disadvantage on the constitution saving throw against exhaustion in high heat. With temperatures below the threshold you can house rules something similar. Generally creatures with fire resistance ignore hot weather.

Quote from RLEE1090 >>

I'm thinking of running my group through ToA and I was wondering if there are any rules related to someone wearing armor and the heat.  I can't imagine someone wearing leather armor in the heat and humidity of a jungle much less someone running around in scale or plate mail.

Any information or suggestions.  Is there a way to play it, without killing the party off due to low AC, having them not wear armor.

Boots of Winterland

I'd image Boots of Winterland can be modified to effect other types of terrain.  Have it grant Resist Fire for hot climates.

Let them ignore difficult terrain for sand (desert) or plants (jungle) or whatever depending on what kind of conditions they are in.

In case, anyone is wondering, the rules for how exhaustion mechanically affects PCs are in a color box, in the Appendix A(Conditions) section of the PHB, near the end of the book.