Table 4.

Incidence of self-reported symptoms of orthostatic intolerance during cardiac autonomic response test battery performed in 16 older adults at the end of randomized 8-h exposures to a range of conditions simulating those experienced indoors during hot weather and heat waves (22–36°C).

Variable	Ambient temperature [no (% of tests)]
	22°C	26°C	31°C	36°C
Number of participants reporting symptoms [No (% of participants)]	0 (0%)	0 (0%)	0 (0%)	3 (19%)
Participant felt lightheaded [No (% of tests)]	0 (0%)	0 (0%)	0 (0%)	2 (6%)
Test terminated early due to inability to remain standing [No (% of tests)]	0 (0%)	0 (0%)	0 (0%)	2 (6%)
Total instances of self-reported symptoms of orthostatic intolerance [No (% of tests)]	0 (0%)	0 (0%)	0 (0%)	4 (13%)

Note: Data reported as No. participants or tests (%). The four instances of self-reported symptoms of orthostatic intolerance occurred among $n=3$ participants. One participant reported feeling lightheaded on their first lying-to-standing test, and then the second test was terminated early because of participant inability to remain standing.