You could maybe add cooling using an elastomeric half-mask-style PAPR. You can cool the body with inhaled cold air- So, back-of-the-napkin math: a PAPR with a hood requires 170 L/min, versus 115 L/min

You could maybe add cooling using an elastomeric half-mask-style PAPR. You can cool the body with inhaled cold air- So, back-of-the-napkin math: a PAPR with a hood requires 170 L/min, versus 115 L/min for an elastomeric half-mask (NIOSH). So if we want to cool 50% RH air (can't dry out those mucous membranes) from 40°C to 22°C, that's maybe 225 W for a hood but just 155 W for an elastomeric mask if you are using TEC/Peltier. So using a mask will save you a lot of power, weight etc. The problem with a TEC is that even with a more efficient mask design running at 115 W, you still have to dump around 300 W of heat somewhere, which is a huge heatsink and fan, bottle of ice water, etc., that will take up most of whatever size using a TEC saves you. At that range, you are probably better off with a micro compressor as shown. They still are a lot more efficient at this kind of thing. One of those would take about 50-60 W to run, and maybe have to dump only 170 W. They are kind of bulky, but I have seen some neat wearable designs and DIY bare bones micro compressors for sale. Then you have to design something pressure-tight with fins to cool the air from the PAPR- and that's kind of a pain since those designs tend to leak eventually- which is why very cheap Chinese PAPRs are not so great. It's doable, but it would be more work than it looks like. (Sorry, can't help, provide links etc, dance card is full folks)