in general, Egg production during moderate heat stress can be improved by increasing the intake of protein relative to energy and it may reach 20-22% but energy requirements will likely increase in severe heat stress. in the same trend Dietary supplementation with ascorbic acid and vitamin E and a supply of cool drinking water have also been reported to improve production during lay but the response to the latter treatment varied with genotype.

Requirments are not for protein per se but for amino acids. Modern feed formulations are based on essential amino acid profiles. During heat stress, chickens should be fed a BALANCED amino acid profile to minimize heat increment resulting from protein catabolism. The level of AA depends on age/production/feed consumption. Please visit https://www.hyline.com/literature/W-36 for an example of AA requirements for laying hens.

https://www.cambridge.org/core/journals/world-s-poultry-science-journal/article/abs/strategies-for-preventing-heat-stress-in-poultry/114CAADF22599E20B2E1192AEE49FE69